How to send attachments if they do not exceed specific size

Problem: You want to send emal notifications with file attachments from your Jira, however, your email server doesn't handle mails where attachments exceeding specific size. You want to email them unless the total size doesn't exceed specific value.

Solution: Use the following template example as reference

#set ($totalLength = 0)    
#foreach ($att in $!issue.fields.attachment)
   #set($totalLength = $totalLength + $att.size)
#end    

#if ($totalLength < 10000000)
  #foreach ($att in $!issue.lastcomment.attachments)
     $jirassimo.includeAttachment($att.id)
  #end   
#else 
     Attachments are too large for sending with email ($totalLength), please download them from Jira
#end

On line 1 we define a variable $totalLength where we store the total size of specific Jira issue attachments (in line 2).

Then on line 6 we compare the $totalLength against the maximum possible size (10000000 or 10MB)