Trying to change my contact email address problem

[halregen]

I have two email addresses. The one I have used in my account, my ISP is not going to use anymore. My ISP is asking its customers to switch to a web email such as gmail. My other email address is a gmail.com one. When I try and change it to this in my account, it says this email address is already in use. I cannot see it anywhere in my account and make it the contact address. I am writing this question here because nowhere can I find the contact us form. How can I change to this email address?

[xenopeek]

You must have registered another account with the gmail address. I can't easily find it here. Please email admin@linuxmint with details and we'll fix it for you. To save time, as we'll ask you to do this anyway, email us from both email addresses to prove ownership of both.

[halregen]

I tried to email admin@linuxmint and got message "the address in the to field is not recognised. Does it have an .org or .com at the end?
ps, I was able to send with .com on the end.

[xenopeek]

My bad, sorry.

See reply in email, should be all fixed and okay now.