Feature request: Add subdomains for email subaddressing

Hi /e/ team,

As I start to strongly consider moving to /e/ as my main email account I start to consider what I would like it to do. One of the things I currently use a lot is subdomain subaddressing. Usual subaddressing is where a +[tag] (or --[tag], etc) is added to the username in the local part of the email address. Subdomain subaddressing allows subdomains to be added after the @, e.g. username@[tag].e.email.

I don't think that Dovecot etc support this out of the box but I believe it can be added.

Please strongly consider as this will allow unique email addresses to be created like in normal subaddressing but in a less obvious way. It will also not be blocked by many websites which don't properly recognise the usual subaddressing scheme.

Thanks :)