How to read file content and send email on Debian Bullseye

[^Bart]

> I have never used it, and I did see that wording in the man page, but it 
> also showed putting all the info on the command line - from, to, 
> subject, etc - so I thought it might be able to use a command line 
> client without needed any GUI interaction.  But I don't know for sure.

This machine is a server without GUI so I must do everything by cli but 
it's not a problem! :)

So mainly I should write a code to find a match between the date found 
on the lftp's log file and the date of the pc, if there's a match I need 
to send an email with "ok" otherwise an email with "ko".

I think it shouldn't be so hard to compare a value inside of a file with 
the date of the machine but now I should understand which is the best 
way! :)

Regards.
Gabriele