Change of primary email address

Hi community, i'm trying to change my professional primary email address to access smartsheet but i've got stuck.

I'm following the instructions detailed here

but i don't get by any means the confirmation request in the new email address i’ve added.

However, if i use my private gmail address the email arrives.

Can anybody help me out?

I already checked outlook rules, junk email etc... in the desktop app and in the online version. Nothing.

Thanks a lot