A workaround is good, but working would be better. 
It may just be the forum doing this, but it looks to me like you have a non-standard dash in your -–send-mail-any-operation=true line - try retyping those two leading dashes so they end up like --send-mail-any-operation=true
You should end up with something like the following with extra info as to what’s going on.
Running commandline entry
Finished!
The operation SendMail has started
Starting - Running SendMail
Running SendMail took 0:00:00:00.019
Failed to send email: System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.
=> The remote certificate is invalid according to the validation procedure.
Failed to send email: System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.
=> The remote certificate is invalid according to the validation procedure.
Return code: 0
Alternatively, you could just follow this (which you probably already know). Try your Command Line feature again but use this (I know, it probably looks like what you’ve already done):
- Select command “send-mail”
- Remove everything from “Target URL >”
- Paste this in Commandline arguments:
--send-mail-to="xxx@gmail.com"
–send-mail-url=smtps://smtp.gmail.com:465
--send-mail-username="xxx@gmail.com"
–send-mail-password=“xxxx”
–verbose
–log-level=profiling - Click “Edit as text” next to “Advanced options” and delete everything in that text box.
- Click the `Run “send-mail” command now" button
Lastly, did any of the topics below work for you? I know gmail works because I’m using it on one of my machines. Unfortunately that machine is not on-site so I can’t check my settings but I do recall having to fiddle with using smtps:// or not and adjusting the ports on --send-mail-url to get things working.