Rejected mails are unreadable

[lilydjwg]

When I check my self-hosted site’s /admin/email-logs/rejected, I find that rejected mails have their body like this:

The correct mail body starts with 谢谢 in UTF-8 (the full body is much longer), and the damaged text is m6Mtyx7x7j+rjuVupyY= in base64.

The mails in the database are already in this damaged state. Comparing that one with the one from the mail server, I find that the mail was rewritten, and I suspect that the email cleaner module scrambled the mail. (But I don’t have enough Ruby knowledge to understand its unique string encoding feature.)

[ToddZ]

Any chance these messages come from an Exchange server..?:

Body of message in /admin/email-logs/rejected is sometimes displayed as gobbledegook

Are these messages sent from Exchange? I ask because I’m familiar with this problem and 100% of the time I’ve seen it, Exchange was the sender and the culprit. My guess is that it’s erroneously sending out an opaque reference to an internal data store via SMTP. In the cases where it’s been solved, the sender did something to fix it.

[lilydjwg]

No. They come from Tencent and Netease. The original mail (I kept it on the mail server to investigate this issue) has no issue with either mutt or Ruby’s Mail lib.