Thank you in advance.

We have verified under TOS6 and TOS7 without problem, you may try with other email address
Who provides your incoming email service. There have been issues, for example, with Gmail in the past identifying (and requiring) special setup for what Gmail perceives as "mail from machines". Likewise possible geo-location issues with service providers - do you perhaps use a vpn? There are probably numerous reasons why email might fail - up to and including the recipient mailbox being full. (Had to explain that to my technophobe sister just this evening).