Limit Receiving Message Size Using Filter

Edit file /etc/vfilters/yourdomain.com and paste the following rule :

Code:

# Exim filter
#Rule1
if
 $message_body_size is above 3M then
mail
to $sender_address
from bounce@yourdomain.com
subject \"RE: $header_subject:\"
fail \"Your message was over 3MB size limit and so it was not delivered.\"
seen finish
endif

Save changes and exit.

Now edit /home/username/.cpanel/filter.yaml and paste the following rule :

Code:

---
filter:
  -
    actions:
      -
        action: fail
        dest: Your message was over 3MB size limit and so it was not delivered.
    filtername: Rule1
    rules:
      -
        match: is
        opt: or
        part: \"$message_body_size:\"
        val: 3M

Save changes and exit.