Unsolved Socket operation timed out

[Thank You]

This is the message logged when I use SMTP to send mail.
It used to work but now it is not working now. I don't know what this mean.
I can put code but It's just from the link "SMTP attachments"
https://github.com/xcoder123/SimpleSmtp_SSL_QT5
And I want to know what this mean ? and what are the ways to solve it?

[SGaist]

Hi,

Did you check server side ?

[Thank You]

@SGaist

Did you check server side ?

Sorry, I don't understand what you mean (what should I check in server side) but
It works for some time and it won't work for some time.

[SGaist]

Then you should use for example wireshark to check what happens on your connection.

You should also monitor your server to see why connection are timing out. It might be overloaded or you making to much queries and getting throttled, etc.

[VRonin]

The project you linked hasn't been supported in 7 years, it might not be working...
My suggestion would be to use simple-mail by cutelyst as it achieves the same goal but the project is properly supported and used by many