How to prevent greylisting?


Office 365 user can`t send message to other service providers, in this case i traced message and find out that our message is greylisted.

How we can prevent that>? Ok, i understand if case is for one recipient, but if there are a lot of them? message does not contain any add or something..

 From message trace:

Reason: [{LED=451 4.7.1 <***@****.lv>: Recipient address rejected: Greylisting in effect, please come back later};{MSG=};{FQDN=mailer.******.lv};{IP=193.111.***.***};{LRT=11/1/2016 7:39:38 AM}]. OutboundProxyTargetIP: 193.111***.*** OutboundProxyTargetHostName: mailer.*****.lv

How we can proceed>?

Hi Armand5,

Greylisting is one of the new ways of combating spam.  Basically, each time a mailbox receives an email from an unknown contact, the mail is rejected with a "try again later" message.  This message happens at the server level, and causes the sender's email system to reattempt delivery of the message at a later time.  So, for normally configured email systems, it will result in the recipient getting your message whenever your mail server retries again (typically within 4 hours).  Once the recipients server receives the re-tried message, it will deliver it immediately (and usually will white-list your address going forward).

Did this issue happen to a specific mail provider? If so, please try testing from another few Office 365 mailboxes and see if you get the same problem there. If yes, it probably means the problem wasn't with Exchange, but with the receiving server. Their greylisting does not appear to work.

In most implementations the recipients server will white-list your address once you successfully send a message to the recipient the first time. If this is not the case (i.e. you are consistently getting these bounces back), you may want to check with the recipient and have them check their configuration settings on their server for their greylist.


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Question Info

Last updated April 28, 2021 Views 7,133 Applies to: