I'm unable to compose or forward an email

Just as the title says, when I click 'Compose' or 'Forward' on an email, I've watched that little circular icon go round and round until it gives up and says no.

I've seen an email from a year ago on here with the same issue: Can’t compose or forward or reply | Virgin Media Community - 5587588 and tried to figure it out myself to no avail, so I would be grateful for some assistance!

If it helps,  I can confirm that I have VM broadband and the effected email account is linked to it. And when I went into Account settings, my email address was listed there.