One of the most important compatibility factors to consider with email is the mobility question. How often do your employees need to access email via mobile devices? That's an important issue because most email hosting providers deliver some kind of web client usable as a default inbox. Almost all of these can be accessed via a mobile device, so if your employees don't need to access their emails on the road that much, then such mediocre clients are probably fine.
The IETF's EAI Working group published RFC 6530 "Overview and Framework for Internationalized Email", which enabled non-ASCII characters to be used in both the local-parts and domain of an email address. RFC 6530 provides for email based on the UTF-8 encoding, which permits the full repertoire of Unicode. RFC 6531 provides a mechanism for SMTP servers to negotiate transmission of the SMTPUTF8 content.
Once you get your custom email address set up, your next task is to create individual email addresses (the part before the @). Fortunately (or unfortunately, if you’re bad at making decisions), the possibilities are endless. You can use your first name, your last name, some combination of the two, generic words like “owner” or “support”, nicknames like “bossman” or “lordofemail”, or any other name you can think of.