E-Mail Size Limits?

Technoman asks: "I work for a company that for the past four years has restricted individual e-mail messages to 5 meg each. We now have users suggesting that this limit is to small and hinders them in performing their job. I would like to know how others are using size limits, and if not how they deal with large e-mails." As human communication over the net becomes more and more complex, the "acceptable size" of an email message will increase. 10 years ago, if you got an email over 10k, something was seriously amiss; but these days, that is just a flash in the pan. Many people rely on email, not FTP to transfer files, and things like a few family portraits can easily exceed several megs in size, so drawing the line for all users may not be as easy as you think, depending on your users and your network. Put simply, if you were the administrator of an e-mail server, what would you set the maximum size of an incoming email message to be, and what would be the reasoning behind said limit?

Comments

Email size

[dpoulson]

Our company restricts emails to 2meg, and we rarely have any problems with that. On the few occasions that a large email needs to be sent, the IT department will temporarily raise the quota. Personally I hate receiving emails over 1 meg in size!

Sounds pretty good

[Tolchz]

Five meg sounds like a pretty good limit to me. In fact it may be a little high. There are still many people on dialup to whom 5 meg is a 35 or so minute download.

My own personal opinion is that if a message is over one meg I put it up on an web site and place the url in the message. If its over 100 megs then I'll choose some format that is easily resumable (DCC, FTP, etc.) .

If people get in the habit of sending massive emails you will start to get mysterious complaints about mail getting rejected. After finally getting your users to give you the returned mail message you'll discover that not all mail servers even accept large mail. Some will reject it as being too big.

Re:Sounds pretty good

[crath]

Our Corporate email system limits email size to 2 meg. The IT department also provides an officially supported FTP/SAMBA server, with Internet facing and Intranet facing access. Got a big document? Send an email with a link to the document on the FTP/SAMBA server. If the receiver needs to save a copy of the document, they copy it off the server. If a copy isn't permanently needed, it will be automatically be purged from the FTP server (depending upon what directory you've dropped the file into: 1-day drop box, 5-day drop box, 30-day drop box, etc.).

Re:Sounds pretty good

[walt-sjc]

This is a bogus argument. There are MANY ftp clients that are just drag and drop. Totally simple to use. The corporate intra / extranet can just be a fileshare.

Don't forget the concept of "training" and online help.

Even the most clueless can handle this concept.

There are MANY methods to prevent search engines from indexing
drop boxes including password access to the dropbox directory / ssl, etc. Again, a bogus argument. Search the net for more info.

Re:Sounds pretty good

[Blkdeath]

Putting a large file on an ftp site that is password protected and sending an email with a url containing the password and username already is just as secure as sending an email.

Of course, you could have a pre-determined location with a previously known username and/or password, else you could tell them something like "The password is the name of your childhood dog of fifteen years." - something that wouldn't be easily known, and would presumably take someone long enough to figure out that the file would already be retreived and deleted.

The added benefit is, you've also then got logs to see if the file has been accessed, which you can't guarantee with email.

That is true, mostly. With e-mail return receipts and MTA "Send Failure" logs are all configurable by the manager of the particular client/servers, wheras FTP logs tend to be a bit more reliable. (Note: I said "tend to be". ;) )

I'd also like to note that Microsoft is planning to possibly remove access to attachments in Outlook altogether, quite probably due to all the bad press about their piss-poor handling of insecure (or "Level 1") attachments.

So what we have is not only a problem where many mail servers will continue to refuse messages greater than 5MB in size, we also have issues with many e-mail providers (HotMail, Yahoo, Softhome, etc.) restricting people to 5MB TOTAL mailbox size, with dial-up users cursing you out for sending them a 45 minute download (they COULD use something that previews the messages on the server and prune the big ones before downloading, but hey ... ), and with umpteen tens of thousands of viruses/worms/trojans that are perpetually mis-handled by retarded mail clients, and more and more companies, ISPs, etc. either virus scanning, removing potentially harmful, or flat-out removing access to all attachments on incoming and/or outgoing mail (for virus and security / confidentiality reasons).

It's very rare that I send an attachment that can't be embedded in the e-mail itself (a .DOC file that could be copy/pasted) or linked to from a webserver (even GeoCities or something would be easy enough - that's point and shoot, and many free web hosting companies virus scan uploads for you anyways).

Size limits ARE needed

[shdragon]

At the company I presently work for, almost EVERY email has an attachment (an excel spreadsheet and a word document). On occassion, those too lazy to type have sent in their scanned TIFF files. I recieved a 48 page TIFF file the other day that 140MB. I deleted it without opening it and told them to re-send in a smaller format. However, everyone else in my office is completely oblivious to the fact of the size of an email and replication. a 10MB attachment sent to 200 people occupies a lot of space REALLY quick. Especially since by default Save sent items and forwards contain the attachments. Everyone else in my office chalks up large attachments to "Outlook being broke" and asks me to come fix it. I then explain to them that they're trying to d/l a large file and just wait (stupid 2B channel ISDN). I recently convinced the Home Office that a size limit of 5MB was needed and exceptions could be made as needed. So far, nobody has needed one. :)

A little education goes a long way. People need to be taught some of what goes on in order to understand why doing XYZ is a bad idea.

Re:Size limits ARE needed

[LWolenczak]

Sounds like an office of the United Way I have worked with.... We had them on a 2B Channel ISDN line after bluestar went out of business, and 95% of the traffic was email, and some russian chick who demanded she be able to listen to russian radio online. They were running exchange though. Even being a linux advocate, until somebody writes a good email storage/access system such as exchange, ms will still have an edge in the market.

In exchange, if one person sends everybody in the company on the exchange server a 20 meg email, the usage of the store is only 20 megs. The feature of being able to access the same account at the same time w/o locks and use the different connections (outlook, imap via moz, webmail) to maniuplate the mailbox at the same time is VERY sweet.

Re:Size limits ARE needed

[FattMattP]

a 10MB attachment sent to 200 people occupies a lot of space REALLY quick.

With MS exchange server, only one copy of the message would be kept and each user would be accessing that message. I wish unix MTAs worked this way.

Software Delivery

[Kiaser Zohsay]

My organization delivers software installers and updates to users primarily via web downloads. And pretty regularly, there is someone who can't get to the download area of the web site for whatever reason (web proxy is down, don't have/dog ate the password, the regular guy isn't here today) who wants us to "just email" him the files. Our main install is just a tad over 5 MB, which straddles the line for some people. Also, there is the occaisional need to get a particular file to an individual user, and email is the prefered method in this case.

Lately, the biggest obstacle is not file size, but attachment filters. Almost nobody can recieve an .EXE file directly (which all of our installers are), and our own incoming filter will delete .EXE files from *inside* a zip file! To send me an .EXE, you have to not only zip it, but password the zip file!

Thank you, MS Outlook, for these innovations in the use of email.

IMAP and Modem

[Alethes]

As a modem user (*sigh*), I find that using IMAP is a great solution for people that attach massive files to e-mails they send to me. I only end up downloading the headers, and I can see the filesize before deciding whether to download it or not.

I've seen a few posts that state that people should use another method like HTTP or FTP, but that doesn't save space on the server any better than sending through e-mail. The obvious best solution is to find a way to send through something that doesn't require a server, like an instant messenger or DCC on IRC, but even then, it should be possible to send huge attachments through e-mail for when no other solution is viable such as users behind firewalls.

Re:IMAP and Modem

[ibennetch]

I've seen a few posts that state that people should use another method like HTTP or FTP, but that doesn't save space on the server any better than sending through e-mail

I think the point to this was that personal items (baby pictures, grandma goes to the disco for her 95th birthday.mov, etc) (sent or recieved during work time) would be put on personal servers rather than work servers, moving the responsibility to keep lots of free disk space from the work admins to whoever is sending the pictures/their home computer/their ISP.

Limits

[NetJunkie]

We have about 180 users and our standard Exchange mailbox size limit is 90MB (soft) and 100MB (hard). Some higher ups get double that, and some really high ups and people that have jobs where they need to keep a lot of old email have none.

I couldn't imagine a 5MB limit. That's fine in a world of text only email, but not today. Too many Word/Excel/Project docs floating around. I do not limit mail attachment sizes because it has not been abused, yet.

DO use email for files

[ka9dgx]

Email is a communications method, it's fairly reliable, and all the users know how to use it to get things to an associate. Just because it might be 30% more efficient to use FTP or some other protocol is not sufficient to force them into learning how to do it. Keep the amount they have to learn down, and let them keep more about their jobs in their brains instead. With the work we do, 100 Megabyte emails aren't uncalled for, even through our 384k SDSL.

I always set up the "size" field, in real numbers (do you really expect a user to know what 10MB is?) so that they eventually learn about email size.

I have no quotas on email, except for the fact that we only have 2,678,837,248 bytes free on our server at this point in time.

--Mike--
Computers - Tools to let people get their jobs done.

Re:Education instead of cushioning.

[Saint Aardvark]

Been looking for a place to throw in my $0.02 Cdn, so here I go.

I work for a small ISP (mostly dialup, a few ADSL). Incoming limit for email is, I believe, 8MB, which I think works out to 5MB for a binary file when encoded. (Feel free to correct me, people.) We have more than a few business customers on dialup, and every now and then we'll get a secretary calling up asking why the quarterly report got rejected by our mail server. The answer, of course, is that it's a 10MB Excel spreadsheet, it's too big, and our mail server refused it.

Email Is Not How You Transfer Large Files, Especially Over Dialup: It takes forever, people use crappy modems (I *hate* hearing the words "ess emm fifty-six") that get disconnected in the middle of a download, and there's no way for them to start where they left off. *Plus*, inna meantime their other email, which is inevitably of the highest importance, is sitting behind said quarterly report, and they can't get at it.

FTP or HTTP, by contrast, combined w/a download manager of some description, would be great. (I was going to moan about how I'd love a Windows version of the insanely great wget, but hey! turns out there is one...sweet!) It would be The Right Thing, it wouldn't hold up their email, and you'd be able to resume if you were disconnected.

I agree that teaching the user is also The Right Thing, and I try to do so when I can. But -- I'm thinking about one customer in particular; I haven't had to talk to her in a while, but she's a good example -- how do I explain this to someone who just wants the frigging report, and to whom it's obvious that her ISP is only standing in her way, and is pissed off as a result?

Part of the problem, I'll admit, is that we don't have a ready alternative right now to hand her: we don't offer FTP space at the moment for our users. I'd love it if we had the intranet-/internet-facing FTP + Samba space mentioned in a post above, but that's not going to happen anytime soon. (Though now that I think of it, it would be easy to set up some space and just tell people about it when they need it; give them access for, say, 24 hours, then kill the account. Hm...)

I'm asking for help on this, not throwing up my hands and giving up. I've figured out the Right (quickest) way to talk people through setting up a dialup connection, or changing their modem settings, or getting the information from them I need to figure out what's wrong. But I haven't been able to figure out how to explain Email + Multi-Megabyte Attachments + Dialup == Bad yet. How do you guys do it?

Re:Who are the users?

[Blkdeath]

If you are an ISP, the users are your customers, and they are right (as customers always should be).

Here we come down to a catch-22 situation. Customers want to be able to a) send as much e-mail as they desire without size limits, b) send said e-mail to as many people as they desire, and c) store all these neat-o e-mails in their folders (in their server home directory, or perhaps in IMAP folders, in their Exchange inbox, etc.) but! BUT! They don't want to spend a couple thousand dollars on a RAID array sufficient to store said e-mail.

When you explain to some of these poeple that hey, you just can't put 200GB on a 120GB disk along with your operating environment and other company file storage, they blink.

Customers are not always right - customers in many cases need to be educated so that they may understand how "this e-mail stuff" works.

Web based 'ftp'

[digerata]

I work for an advertising agency where we regularly transfer files up to 2 gigs in size. Our problem was that people wanted something faster than Fedex'ing CDs and we had too many people getting mad when our mail servers crashed because some one emailed a 2 gig file.

Our solution was to create a web based file sharing system that supplements your existing email service. This system is available for internal employees as well as external employees. Its simple. If you need to send a file, you login in to the service (LDAP enabled so one password for all systems) and fill out a form with the recipients email address and then attach the file(s) you want to send. The recipient receives an email from the user and the location to pickup the file. This is all done via HTTP but we recently added support for a client side java application that will download the file via FTP transparently. Its all *extremely* user friendly.

An interesting aside is that to correctly implement 'view attachment' in a browser window and 'download attachment' to your harddrive functionality, we have to send a bogus MIME Type for the file so that IE will actually download the attachment instead of opening it in the window. (Word doc, PDF, etc.)

Another option that we explored was to use WebDAV. The issue we ran into there was that WebDAV is not supported natively under Mac OS 9 or Win 9x.

Also, was this written with .NET? Hell, no. J2EE all the way.

Education and alternatives

[gozar]

The hardest part of using FTP as a solution is that it requires the recipient to have a FTP client on there machine, but that isn't the case. There are several web based FTP clients (such as web-ftp) to make it simpler for everyone to place files on a FTP server.

I think even 5MB limit is too large, especially if you are on dial-up (I hate it when someone sends me a 2MB movie...)

I am

[MarkusQ]

...if you were the administrator of an e-mail server, what would you set the maximum size of an incoming email message to be, and what would be the reasoning behind said limit?

I am the administrator of an e-mail server. Our limit is 5Mb. I found that to be a reasonable elbow in the curve between most of our trafic by message count (e.g. Things like "I'm running late...could you hold off processing xxxx for me?" and "No.") and the majority by size (e.g. "Here's a copy of that set of porn CDs I stole"). It only affects legitimate bussiness trafic about once a year (we don't use MS Office, etc.) and it cuts our total storage volume by about 80%.

-- MarkusQ

AOL doing something well for consumers?

[EaTiN cOfFeE bEaNs]

Correct me if I'm wrong on this one, but isn't AOL is the only e-mail service used predominantly by consumers that doesn't have a low space limit.

11MB mail box, 20MB for attachments, for a reason!

[chris_martin]

I set up an 11MB quota for each of our 4000 users. But I allow a larger attachment and you have a 5day grace period to delete mail. So each user can receive up to a 20 MB attachment and as long and they download and delete it off the server they will still receive their email.
Before I set up the enforcement of the attachment size I had a teacher try to email an audio recording of her class to her supervisor. It was a 44.1KHz stereo AIFF file and it was an hour long, so it was around 640MB. Who needs napster when you have email! Most users are pretty good, but we have around 1% that are constantly over quota.

Re:education is the only way

[Bastian]

So true.

At my work, nobody explained to the users why they shouldn't send large e-mails, and a limit wasn't set. Of course, there was they day when a chain letter involving a fairly large image file showed up, and everybody sent it to everybody else. The amount of space the individual copies of this chain letter took up on our server's hard drive grew exponentially until the partition the mail was stored on filled up, and mail services shut down because there was no room to fit incoming mail.

Explain to users this danger and show them some method of breaking files up or transferring them in other ways. In my experience, you have to either by extremely prodigious or extremely unprofessional to create a standard office document that exceeds 5meg.

Mail size limits everywhere!

[teqo]

As many other postings suggested, 2 megs is a widely deployed limit. Whenever you think about your own corperate mail size limit, keep in mind that even a 100 meg limit won't help you if the sites you send mail to have a way smaller limit. Since you never know what limit your mails will hit on the recipients' (or forwarding) servers, always keep it considerably small, or it will be rejected by the recipent's server... Better have it being rejected within your own network, so you don't waste precious bandwidth to the outer world...

I saw people sending out their whole mp3 collections in 30 meg-sized mails, I saw others suffer from 5 megs holiday pics in their mailboxes accessed by humble 56k modems and having to give them a POP3 primer on the phone to have them delete that stuff ... Yes, mail isn't ment for big files, and besides this orthodox opinion, it still isn't very practical to send huge files per mail.

I would go for the send-links-in-mails-to-files-on-{web,file}servers idea, maybe protected through SSL, temporary passwords and having the files auto-deleted after three days or when having been fullydownloaded one or two times or whatever... (Proposing some minor access security for the files being made available, I wonder how many of these suits 'needing' unlimited mail sizes protect their files when sent by mail? I have never seen a single member of this demandish breed (being subject to this publication) being able to handle PGP/GnuPG/whatever, they often consider that as another evil trick by notorious sysadmins, since security measures hinder them in doing their work properly, just as mail size limits do... So much for ranting :)

yEnc: The Answer

[Istealmymusic]

SMTP was never designed to handle binary files at all, which is why binary files are encoded into text, which increases their size by 30%.

I'm still waiting for yEnc to be officially incorporated into Outlook and other e-mail clients and recognized automatically. XXE/UUE/Base64 adds 30-40% overhead, while yEnc offers 1-2%. All communication channels on the Internet today are nearly 8-bit clean, but certain characters cannot pass through unmolested - yEnc only encodes such characters.

yEnc has shown widespread acceptance in Usenet, I'd like to see it used as the de-facto format for SMTP mail. Electronic mail's "push" nature makes it extremely useful where FTP/HTTP is not (although IRC DCC is) and I'd enjoy having the pleasure of subscribing to mailing lists which send out multimedia or other forms of large content and having it delivered, just like postal mail, right to my desktop or a nearby ISP mail server. Who is with me?