The SMTP server port settings changes for affected clients
Some ISPs (Internet Service Providers) block port 25 as a spam prevention measure. If your ISP blocks port 25, use port 2525 or 587 instead.
Please refer to the KB at below:-
Outgoing e-mail: Configuring SMTP
Thank you very much for your attention.
Best Regards,
Verve Art Support
5th Oct 2016