Hello and welcome to our forum.
E-mail is currently managed by Roundcube open source IMAP client integrated with Epesi - addressbook and archiving.
You may want to look for a plugin for Roundcube that handles .ics files, but even then it would work only with other calendars like Google Calendar.
I would suggest to use first another e-mail client - for example Gmail, Mailspring etc. and configure it to handle .ics, you can also open e-mail on the smartphone and it should work. Then use Epesi e-mail only to archive the message.
Unfortunately Epesi does not handle .ics or vcard format.
There was an attempt to do something about it: https://github.com/jjjj12212/EPESI-Ical
