Delta Chat Version: Delta Chat for Android v2.49.0 -- but I assume this might be a rather long-standing issue.
Any initial message without e2ee seems to be rejected by Posteo's SMTP server with the following error message (retrieved from the "Connectivity" screen):
Error: Send error: permanent: 5.7.1 message content rejected
I initially encountered this issue quite a while ago after using "Add Contact Manually" to contact a previously unknown address-contact. I confirmed today that this issue still persists in v2.49.0. This issue does not occur if the address-contact initiates the conversation. In this latter case, replying to the contact's email works as expected.
Today I discovered that this issue also affects the legacy SecureJoin protocol (prior to SecureJoin v3, see #7396). If I scan a legacy SecureJoin invite code (without the &v=3 parameter), Posteo rejects the initial message. This effectively breaks legacy SecureJoin for my main email account.
I did not dig deep enough to figure out what is transmitted on the wire in these cases. If anyone manages to get an SMTP dump for the two cases described above, I'd be happy to submit manually adjusted variations of this dump to Posteo's SMTP server in order to figure out where exactly the problem lies.
Delta Chat Version: Delta Chat for Android v2.49.0 -- but I assume this might be a rather long-standing issue.
Any initial message without e2ee seems to be rejected by Posteo's SMTP server with the following error message (retrieved from the "Connectivity" screen):
I initially encountered this issue quite a while ago after using "Add Contact Manually" to contact a previously unknown address-contact. I confirmed today that this issue still persists in v2.49.0. This issue does not occur if the address-contact initiates the conversation. In this latter case, replying to the contact's email works as expected.
Today I discovered that this issue also affects the legacy SecureJoin protocol (prior to SecureJoin v3, see #7396). If I scan a legacy SecureJoin invite code (without the
&v=3parameter), Posteo rejects the initial message. This effectively breaks legacy SecureJoin for my main email account.I did not dig deep enough to figure out what is transmitted on the wire in these cases. If anyone manages to get an SMTP dump for the two cases described above, I'd be happy to submit manually adjusted variations of this dump to Posteo's SMTP server in order to figure out where exactly the problem lies.