Problem with SMTP port 255 in Sophos UTM 9.602-3.1 Home

Question

Good day to the whole community, first of all I want to tell you that I am very new to the topic and I am trying to implement the Sophos UTM 9.602 Home. I have everything installed and with some basic configurations and it works great, my problem is presented with the email accounts that I have configured in Microsoft Outlook (they are pop accounts) which use the SMTP port 255 and some of the firewall blocks it with which I can not send any mail. The strange thing is that the send / receive test that the outlook does when setting up the account does it well and does not give any error, but when I generate a new mail I can not get it to come out. I have the SMTP Proxy deactivated, please if someone can help me, I am going to thank you very much since I have been working with this issue for a couple of days. 
 Thank you 
 Javier

BAlfson · Accepted Answer

Thanks for saying a lot of things I didn't take the time to. We agree - I never recommend using the SMTP Proxy without an owned domain with its own mail server. Looking back at his first post, he doesn't have the SMTP Proxy activated. 
 Cheers - Bob

DouglasFoster · Answer

This sounds like a common Outlook configuration error, which has nothing to do with UTM. In your Outlook profile, change the mail account, the choose Morel Settings, then Outgoing Server tab. Check the boxes for "Outgoing server requires authentication" and "use the same settings as my incoming mail server". The test works because the incoming mail is tested first, making you authenticated. 
 SMTP Proxy is only useful if you have a mail server inside your house. This does not seem to be your situation, so leave it disabled. 
 Since you are using POP, you should use the POP proxy. Most residential mail systems have pretty weak spam filters. The UTM POP proxy gives you a little extra protection, because it will replace a suspicious message with a placeholder. If a false positive occurs, you should be able to view it using the vendor's webmail interface. (Not necessarily wise, but possible.)