I have a one-letter "a@domain.com" email address and I often have issues with services saying "your password contains your email address". Basically means that

I have a one-letter "a@domain.com" email address and I often have issues with services saying "your password contains your email address". Basically means that my passwords cannot contain letter "a". Find it amusing since I have to replace all "a"'s in my 1password-generated 30-char password with something else.