Jason Hendriks on "[Plugin: Postman SMTP Mailer/Email Log] 'Invalid email address' error on Zerif Lite"

sales@You-niq.com <p>

Yes, as Postman already noted, p is clearly not a valid email address.

I don't do support for the Zerif theme. Please post on their forum so they can fix the issue for you: https://wordpress.org/support/theme/zerif-lite