Thanks for posting your working code!
some minor suggestions:

....
eval 
{
    local $SIG{ALRM} = sub { die "MailFile Timeout\n" }; 
    alarm $mailfiletimeout; #20 seconds
    
    $sender->MailFile(...);
    alarm 0;
};

if ($@) 
{
   die unless $@ eq "MailFile Timeout\n"; # propagate 
                                          # unexpected errors
   logerror("Timeout ....);
   return 0;
}

# no else{} is required, what "else" ????
# Simplify the logic - reduduce levels of indendation
# if there is a serious error we don't get here...
# there is no "else"

# proceed with more code...
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