SMTP Auth - missing invitation on shared Hosting

[gitkald]

Event invitations, on a shared hosting hosted Baikal instance, are sent, but Goolge seems to swallow these invitations completely.

The reason is probably that their spam restrictions are too high, so that messages sent without smtp identification are not accepted. (There is not even an indication of rejection)

There are already countless postings on smtp authentication here. Is something planned or already being implemented?

Unfortunately, baikal is not really usable in this way, even if the calendars work in purely functional terms.

Kind regards
Malte

[Tntdruid]

Googel block if you don't use dkim + dmarc and spf. Baikal send is a normal phpmail.

[gitkald]

These options are actually set. Normal mails also arrive. Only the invitations from Baikal do not. And there seems to be a problem with phpmail.

Invitations to non-Google mail addresses also arrive. Until a few months ago, all invitations to Google addresses arrived. As a tip, someone told me that they had drastically increased their spam guidelines. And if you read here on github, there seem to be problems with phpmail without identification.