How to fix the "421 RP-001 The mail server IP connecting to Windows Live Hotmail server has exceeded the rate limit" problem?

email limit live hotmail
Ryan picture Ryan · Dec 5, 2008 · Viewed 15.9k times · Source

We run a large online community in the Netherlands. Because of that we send a lot of mail to the hotmail email addresses of our members. Recently we have noticed that not all mail is reaching our members, because we have hit a certain limit or so it seems.

Google doesn't give a solution (yet) but we see a lot of others having the same problem. Note, We have added (since long) SPF records for our domain, in TXT and SPF types. What else can we do to tackle this problem?

// Ryan

Answer

bzlm picture bzlm · Feb 19, 2009

421 means that the service is not currently available, and that the client should try again. This could be for any number of reasons, including trying to discourage you from too frequent mailing if Hotmail thinks you might be a spambot.

Why not simply let your outbound smtpd queue the mails and try again?

Why is "not all mail reaching your members"? Don't you try again if you get a 421 response?

EDIT: Do what sqook says.

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