Use e-mail service included with VPS?
 

As I look to decide where to take my personal e-mail with own domain, I have been testing a variety of services including posteo, fastmail, and mailbox.org. Obviously I care about security/privacy (to a degree--I understand how un-securable e-mail is in general) and I kinda favor non-US hosts (perhaps irrationally).

It happens that I have an account with a vps provider where I have a server I use as a vpn and test lab for various linux-based experiments. I pay $6/month for this. Turns out that as a customer of this vps company, I have access to email hosting at no additional cost. Not me running my own email server on my vps, but the hosting company offering email services to its customers as a perk. I checked it out, and they are running Postfix and Dovecot, using a plain-Jane Roundcube as a webmail interface. They allow me to generate my own dkim key for my domain and upload it to their servers to sign outgoing mail. They provide the necessary info for me to set up the proper SPF and DKIM dns record. I can create unlimited aliases. The first 5000 emails are free (per month) along with the first 1 GB of storage. After that they charge by the email some small amount.

Given that I already pay a monthly fee to this company for a virtual server, and that my modest requirements will not come close to exceeding the monthly limits, and that I use Thunderbird or K-9 Mail > 90% of the time (and not the web interface), what good reason exists for me NOT to use this as my main e-mail service? Shouldn't I just quit looking to spend another few bucks a month at a separate provider and set up shop here?

Please give me your ideas about potential problems that I might be overlooking.

I don't see any potential issues with you using them. If you needed contact/calendar mobile sync or other features their might be. But for just basic email usage especially since most your time will be on Thunderbird / K9mail, you should be good!

Their spam& virus filtering probably wont be all that good. OTOH you can just move the hosting if it becomes a problem.