Hello Angmar,
I'm currently facing the exact same issue: I have a bunch of email+modifier@customdomain.tld which I'm not receiving since June 1st (my domain migration). I just realized that 😢
I just added a catch-all email (*@customdomain.tld), and I'll wait 24-48 to see if this works. This is really a pity because I have a rule that forward group@customdomain.tld to a Google Group, and, IF the catch-all email works, I highly doubt it would transfer the group+modifier@customdomain.tld to the Google Group, but rather to the target of the catch-email.
Let's see how it behaves.
In the meantime, if anyone has feedback on this kind of setup, please share your knowledge.
Thanks!
