I think we can get this fixed, Mailspring excludes common “transactional email addresses” like “support@” and “info@” from auto-contact creation because for some people it pollutes autocompletion.
I think that if you start typing info@, we should definitely autocomplete those though. There’s a PR open that should address this here: Fix contact autocomplete when no legacy accounts are loaded by ejbiker93ss · Pull Request #2824 · Foundry376/Mailspring · GitHub. It needs a bit of cleanup but I’ll see if we can get it merged in the next release.