

Hosting your own email server is a challenge, as DMARC, SPF and random hand waving by email companies (who should know better) make it needlessly problematic.
There’s also the issue of whether your home ISP allows inbound email ports (25/tcp, etc). A lot don’t.
It’s possible(?) a hosting provider can do decent email, but I tend to think of that like 1990s-era ISPs who provided email: liable to be discontinued at any time with little/no notice and not portable.
But it’s your call. Good luck.
I encounter this mostly with manga. (I’ll not rehash what others have said).
FWIW, and in that use case, I deal with it by renaming x5 to x5.0 so it will sort before x5.5. And then usually put both into an x5 directory and then zip that into a CBZ.