Admins Accuse Microsoft of Hotmail Cap

kurmudgeon writes "The Register is fielding reader tips that Hotmail has placed Draconian limits on the number of Hotmail recipients who can receive an email. The first 10 Hotmail addresses included in a mass email go through just fine, according to these reports. But any additional addresses are returned to sender with a message that reads: "552 Too many recipients." (Microsoft denies it has placed any such restriction on the number of senders.) This would appear to be a violation of RFC 2821, which states: "Rejection of messages (for excessive recipients) with fewer than 100 RCPT commands is a violation of this specification."

Comments

People still use hotmail?

[heptapod]

There are hundreds of free alternatives available and a simple Google search brings up numerous email forwarding services that can take the sting out of changing email accounts.

Re:And the problem is...?

[Kelson]

No - for every recepient that they reject, they are, in effect, blocking those recipient from receiving the intended message.

The proper reaction of a sending server to a temporary error is to try again. Per that same RFC, the server should be treating '552 too many recipients' as a temporary error.

Yahoo does the same thing at 30 recipients, though they issue the more proper 452 error code. The first 30 recipients at Yahoo get the message, then the sending server retransmits to the remaining addresses.

RFC 2821 is not (yet) a standard

[Eric Smith]

This would appear to be a violation of RFC 2821, which states: "Rejection of messages (for excessive recipients) with fewer than 100 RCPT commands is a violation of this specification."

RFC 2821 isn't a standard, though. It's on the standards track, but it has not yet been accepted by the IETF as a standard. The current SMTP standard is RFC 821, also known as STD 10. RFC 821 says:

recipients buffer

The maximum total number of recipients that must be buffered is 100 recipients.

TO THE MAXIMUM EXTENT POSSIBLE, IMPLEMENTATION TECHNIQUES WHICH IMPOSE NO LIMITS ON THE LENGTH OF THESE OBJECTS SHOULD BE USED.

This only requires that up to 100 recipients must be buffered, but doesn't explicitly state that there is any requirement to deliver to all 100 such recipients, nor that recipients cannot be rejected for some reason other than running out of buffer space.

You think MS is bad? Try Yahoo!

[statemachine]

Yahoo has been junking all e-mail from my domain. Yet, my domain has been around since '99, has an SPF record, and has not been on a spam blacklist ever. I don't run any lists, and usually these e-mails are only directed at one recipient.

When I contacted Yahoo, I was referred to a broken web form that supposedly would direct me to a place where I could whitelist my domain, or at least make it less spammy-looking to Yahoo. Upon further attempts to reach them, I only received automated responses, but no answers to my questions.

I am not the only one who has had this problem sending e-mail to Yahoo accounts. Ironically, just Google for all the discussions on how Yahoo doesn't care.

Sending e-mail to GMail accounts works just fine for me. None of my messages show up in the spam folder. This is an indicator that the problem lies with Yahoo, and not with my domain.

Re:And the problem is...?

[Obfuscant]

Refer to RFC2821, which is the RFC that MS is being blamed for violating by not allowing 100 RCPT commands per session. Normally, you are right, 5XX is fatal, but 4.5.3.1 Size limits and minimums says:

RFC 821 [30] incorrectly listed the error where an SMTP server exhausts its implementation limit on the number of RCPT commands ("too many recipients") as having reply code 552. The correct reply code for this condition is 452. Clients SHOULD treat a 552 code in this case as a temporary, rather than permanent, failure so the logic below works. SHOULD means "unless you know what you are doing and have a good reason to do otherwise." The "logic below" is that the sending server removes the ones that were successful and tries the rest again later.