bounce emails

hello mautic support,

i have just uploaded a test list with 30 gmail and hotmail accounts, that my friends have access to and the emails are legit and working just fine, but mautic keeps tagging them as email bounced under the name of incorrectly formatted email address.
what went wrong ? tell me what to check please thank you

i’m using my own smtp that i created, using postal it’s a open source platform that helps create an smtp …

i don’t really know but it use to send perfectly, i reinstalled mautic and the problem still exist …