I need to use an alternate SMTP port / I cannot send email correctly from my email client.

Posted on Sunday, July 1st, 2018

Some Internet Service Providers block access to eMail on port 25 due to security concerns and to prevent the sending of spam emails.

If you are unable connect to your mail server via SMTP on port 25 using a mail client, you
can may use port 26 or 587 instead.