I am pretty sure I know the answer, but wanted someone who understands emailing in Epicor better than me to confirm.
Can I have 1 Company in Epicor with multiple email domains? To clarify, this would be 2 separate instances of email domains, not 1 domain with aliases.
We’ve got multiple email domains for our salespeople. Epicor doesn’t seem to care what we have on our email alert BPM’s (we use outlook groups, and maintain the contacts there, but some are hard-coded within Epicor). I’m not our reporting guy, but I don’t think SSRS cares either…
Is there something in particular you are concerned about? Most email address fields aren’t going to care what domain is used.
The only real limitation I can think of is that the Default From Email address used by Epicor to send emails, that is of course limited to a single email address, but could be overridden in your BPMs, etc.
I probably did a terrible job explaining in the initial post, which is why I came here to ask. 
So the responses are greatly appreciated. Here goes round 2 for trying to explain it correctly.
We recently purchased a company. We have 365 with multiple domains (not sure if I am using correct terminology) and they have 365 with one domain. Both 365 accounts are still separate and are not under 1 account. I guess the better question is, can Epicor handle two email accounts (still not sure if that is the correct terminology)?
You can try adding second email as an alias.
Quick sidebar: My Default ‘from’ is linked to a 365 account, In my BPM I am changing the ‘from’ field, but it is still coming from the default 365 account. Does the override only work for SMTP?