Issue Bizzare issue with e-mails

[Ivica]

Hello

We have a weird issue and i'm having trouble finding what is wrong.

Symptom: mails don't go towards hotmail. Now before you start rolling your eyes we are not blocked by them, we are not on any blacklist, our Ip reputation is 100/100. We are not getting any bounce back messages, no errors or anything similar. Mail is successfully sent but it never reaches destination.

If we use hotmail to send to that mail first, it comes normally, then if we use replay to it will come to hotmail. So it is not blacklist issue. There is probably something wrong with mail server but I cannot find anything. Nothing out of the ordinary in logs.

Btw is it normal that there is not trace off "to" in your logs? I mean not a single log line about e-mail account's we send to. Not just hotmail, any kind of outgoing inboxes. even those that work fine.

TLDR
If we sent to hotmail it will not work, if we replay to hotmail it works. Weird.

 

[Bitpalast]

The symptoms that you describe are pointing to a malformed mail header on newly created mails. Replys and new mails are handled exactly identical from a technical point of view. There is no difference in the transport scheme, protocol, how addresses are evaluated and how mails are delivered. Normally in this situation it means that the address you are sending to is malformed.

Please check the exact spelling of the recipient entry of a mail that is not transported to hotmail. Does it contain extra spaces? Does it contain a semicolon or a colon or a comma? Are the brackets set correctly, e.g. <[email protected]>? Is @hotmail.com spelled correctly?

Sometimes users confuse the visible recipient address with the "real" address, e.g. when they are using an entry from an e-mail address book where the visible address looks correct while the actual technical address that is stored for the entry is malformed.