|Possible reason||What to do||Other comments|
The user name and password of the SMTP+ user are not correct
The sender's domain is not one of the authorized domains.
|You will typically need to enter a second-level domain, since email addresses are typically at the second level. That is: you will typically enter mycompany.com and not www.mycompany.com |
You do not "need" to authorize at the domain level. You can authorize specific email addresses. It's whatever works best for you. See below.
The sender's email is not one of the authorized emails.
|You do not "need" to authorize specific email addresses. You can authorize entire domains. It's whatever works best for you. See above.|
|The port used is not "open" in the Web server where the message is being sent.||Try another port. For example, if you had to specify a port in the email client and you entered port 25, try changing that to 2525 (or another port supported by SMTP+). If nothing works, ask your server administrator which ports can be used.|
SMTP+ supports a variety of ports: 23, 25, 26, 587, 1025 - 5000 (limits included)
The port used is not supported by SMTP+
|SMTP+ supports a variety of ports: 23, 25, 26, 587, 1025 - 5000 (limits included)|