Unable to send emails with 'Hide My Email' after macOS 26.1 update on iMac M1

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Level 1

15 points

Unable to send emails with 'Hide My Email' after macOS 26.1 update on iMac M1

prior to macOS26 Tahoe, on my iMac M1, macOS26.1, in Mail.app I was able to send mail message to new contact using a "Hide M Email" creating a random email.

Since update to mac0S 26.1, I I am unable to 'send' after creating a new random email in the Mail.app::

The error message is Apple (out) Server is not configured to send using the hide my new random hide my email..... it defaults to my AppleID email ( @mac.com which I never use to send messages, instead all my mail goes through my @iCloud).. I am asked to select a Server ... there is usually two Apple options (one says it's offline).

Appreciate advice about this 'set up' issue, please Garry, Super Senior, non-techo

[Re-Titled by Moderator]

Original Title: Unable to send

iMac 24″, macOS 26.1

Posted on Dec 8, 2025 11:03 PM

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Answer 1

ken6401

Level 1

10 points

Jan 13, 2026 1:26 PM in response to ken6401

Ok so I only had this on my MacBook Air M4 and not my Mac mini, so perhaps a problem with the upgrade itself corrupting the mail settings in some way.

I've got back to a working system (for now) by:

In Internet Accounts, remove all email accounts (in iCloud, you disable Mail).

Then, delete these

~/Library/Containers/com.apple.mail (if it exists)

~/Library/Containers/com.apple.mail-shared.plist

~/Library/Mail/*

If it lasts for more than a day or so I'll be calling it fixed.

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Answer 2

Dec 9, 2025 1:04 AM in response to nonTecho

✔ Fix = choose the correct outgoing server: smtp.mail.me.com

✔ Delete “Offline” or “mac.com” servers from the SMTP list

✔ If needed, toggle iCloud Mail OFF/ON

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Answer 3

ken6401

Level 1

10 points

Jan 12, 2026 7:24 AM in response to nonTecho

I agree, I have the same issue and those steps did not help.

My whole iCloud email settings stopped working for all accounts 1 Hotmail and 1 iCloud.

I removed the hotmail (exchange) account and created a new SMTP outgoing setting for the iCloud account and can send normal iCloud emails, but when I try and send (reply) from a hide my email address it is rejected with the no outgoing server error.

Seems like a bug because the outgoing settings for that account work fine for non-hide my email addresses.

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Answer 4

Jan 16, 2026 9:20 AM in response to ken6401

I am seeing this issue on both my M1 Mac mini as well as M4 MacBook Air, both running the latest macOS 26.2. The error does not spawn on iOS devices or an iCloud.com, only on the Mac.

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