Fix Apple Mail's 'Invalid Email addres. Please enter a valid email address for this account' error

or, how to overcome Apple Mail's stunningly bad error message when changing an existing account's login details

Posted by Orville Bennett on 16 February 2024
Read time: about 3 minutes

Having finished a recent migration to a new email server (goodbye, Linode1) I started the process of updating my email clients. I had a wide swath of clients to update: K9 for android, Mail for iPadOS, Mail for Mac, Canary for iOS.

The Mac client setup went fine as I had not actually ever setup on my Macbook Pro since purchasing it years ago. I had been using Thunderbird for Mac, and prior to that Canary, and prior to that MailSpring. Yes, I am unsatisfied with the state of Mac email clients.

The Problem

All these updates were going well until I started making the updates to for iPadOS. To be clear, this is the native app that Apple provides. It gave me a clear, but also terribly wrong error message which said:

Invalid Email addres

Please enter a valid email address for this account

That seemed pretty straight forward. I must have typed the email in incorrectly right? Except the email address was valid. I never touched the email address! The thing I had updated was the mail server's hostname.

Thankfully I found the solution referenced on the Apple discussion forums.

I had created aliases for this email account and when I updated the mail server's new hostname that "Invalid Email address" error was, apparently, due to the fact that was trying to "validate" aliases as login accounts. I put validate in quotes as no request was actually made to the mail server, so I don't know what was actually trying to do.

The Solution

The solution was to delete all the aliases leaving only the login account. After saving the new settings I could go back and re-add all my aliases. Which is what I did.


It's all about the Benjamins. Linode still has great customer service, but I am determined to not pay more than I need to for my VPS (cloud hosting). Linode raised their prices on the plan I was using ($10/mo - 2 GB RAM), so I bumped down to a $5/mo plan (1 GB RAM) until I could spin up something on a cheaper host. Instead of paying $120/year for a 2GB RAM linode, I would have been paying $144/year for that same 2 GB RAM linode. $24 more for no appreciable increase in value is not something I'm going to do. I found a (European) host and now have two separate VPS's. One Linux and the other FreeBSD, both with 8 GB RAM. Total cost? $143.76/year. I get a host with both (significantly) more RAM, and more CPU cores. More value, and I pay more money. This is the way.