Mail keeps telling me to "Update My Forward To" Email Address

'Out of the office' messages and 'forward-to addresses' are features ONLY supported by settings on the Mail server on the Internet. Apple Mail can not change these settings.

Use WebMail (a really fancy name for a very bland way of accessing your mail server through a web browser.)

Make sure your settings are correct.

Ditto. Just started happening for me today.

Very frustrating.

You had to walk by the answer to post your query.

If you do not understand that, please list what email service provider you are using.