Persistent problem with Outlook 2016, relay.force9.net and AVG

[#1]

Has anyone out there successfully used:
Windows 10
AVG security

Outlook 2016
force9 pop

My incoming e-mails all arrive, but my outgoing e-mails are not sent.  (The attached relay.png is repeatedly displayed.)

I can use force9 webmail to send and receive, but wish to use Outlook.

Are there some tweaks required for this combination of software products?

Thanks in advance for any help.

[#2]

Try this link:
https://www.plus.net/help/archive/email/microsoft-outlook-2010-setup/?supportarchive

[#3]

This could be a port setting problem. Most of the world use an encrypted port for sending emails and this is the default Outlook setting. Plusnet do not encrypt email traffic. Go into your email settings and check that the send port is set to 587 (preferred apparently) or 25.

[#4]

AVG tech support were able to resolve this issue.

Thanks to those who took the time to try and help.

Moderator's note by Mike (Mav): Post released from Spam Filter.