Using Protonmail with a receive-enabled Cloudron domain - splitting mail?

[ianhyzy]

Hey folks, I have my personal domain (ian.gay) on Cloudron and right now it's fully configured to send and receive email. I was looking at moving just my personal email to Protonmail for a few reasons but it seems difficult (if not impossible?) to split mail like this.

Would I need to receive everything on my cloudron first, then forward to proton, or is there a way to use a mail subdomain on Cloudron (like cmail.ian.gay having a different mx than ian.gay) ? Or is the only solution just to set it to send-only and use a different address for Cloudron? Has anyone tried something like this?

[girish]

@ianhyzy as in, you want some mailboxes on Protonmail and some on Cloudron for the same domain ?

[ianhyzy]

@girish right, I'm assuming it's not (easily) possible but wasn't sure if there was anything I didn't know about that makes it possible.

[timconsidine]

@ianhyzy Haven't tried it but sounds useful and also do-able.
I have the reverse : primary email on protonmail and would like a subdomain of primary to be in cloudron.
I think it's possible.
At least for because I use the wildcard DNS approach.

[girish]

@ianhyzy yeah, it's not possible since email delivery works at a domain level and not mailbox level. The best you can do is to have email of some mailboxes forwarded from Cloudron to Protonmail or vice-versa. In the next release, we are trying to make email forwarding setup simpler, so maybe it will help in this situation.

[robi]

It would be an interesting feature to have the mailserver for a domain be able to recognize that a mailbox it is receiving for is elsewhere and redirects the connection there.

This would be at a higher level than where forwarding happens.

Just like when one moves IRL and tells the Post Office the new address.

Similar to 301/302 HTTP redirects.