I've been using the exact same system for years, and I'm glad to hear of others doing the same.
Most of my incoming mail that I might reply to comes to only a handful of specific addresses -- so I create an identity for each of them. The other dozens-and-dozens of email addresses I receive email from (corresponding to various companies/websites I work with), I rarely need to reply to (often they are newsletters), so I don't bother with specific identities.
I also use the catch-all, both for incoming email routing, and for the identity on each of my 2-4 domains. On those occasions where I want to reply from a specific
SomeSpecialCompany@MyDomain.com , I can quickly edit the From address in the email window before I send. No problem.
Quick question for others using this system.... Have you ever suddenly stop receiving email (like a newsletter) from a particular sender, when you know you should still be on their mailing list? This has happened to me a few times, and I wonder if the senders in such cases are somehow blacklisting the outgoing email, thinking it's a spam recipient, being that the username is their website/company name.
For example: I used to subscribe to Meetup.com as
meetup@MyDomain.com . At some point their emails simply stopped arriving. It was very frustrating to not get alerts, etc. Well, I logged in and changed my registered email address with them to something completely different, like
meat4849@MyDomain.com, and suddenly emails began again. Hmmm...
I have a few other companies in this situation, but I still need to sit down and update my email addresses with them, and see if it works.
But I wonder if this is a common problem for users like us who manage our email addresses in this way. (Also, I wonder if this could be a spam handling bug on the receiving end - by Fastmail.)
Apologies if this post is considered hijacking this thread. If so, I can delete and start a new thread.