Can't change email - invalid

[Josh]

I am trying to change my Atlassin account email to use a new domain. When I try to change it, I get the error: "The provided email address is not allowed, please use a different one"

The email is at my own domain. I use this domain for emails on all my accounts. Why can't I use this? Why is it not allowed?

I tried to submit a ticket with Atlassin support but don't have a paid account, but this seems like something they will need to resolve. I do not want to post the email publicly here but am happy to provide it to a support member if needed.

[Josh]

I am using SimpleLogin mail server. Apparently this is not allowed? Can I be given an exemption by support since I am not a spammer and have had an Atlassin account for many years?

If this is not possible, should I change my MX record temporarily so that the email can be added? Is that what you are looking at when determining an email is not valid?