User trying to add second email address

One of my users is trying to add a second email account but when they are asked to verify the primary account (gmail) they get this error.

Error
XDOMAIN_MERGE_FORBIDDEN

how do I get this fixed?

Welcome to the Forum @Stuart_Pallen and thank you for reaching out!

Please have a look at the following guide article to learn the steps to add a second email address: https://asana.com/guide/help/fundamentals/settings#gl-add-email

If your colleague has followed all the steps outlined in the Guide and continue to run into this error message I would recommend him/her to reach out to our Support Team who will be able to manually add this second email address for him.

To contact our Support Team you just need to follow these steps: How do I contact support

I hope this helps Stuart! Please let me know if there is anything else I can help you with!