Quick note on how to increase the mail size limit in postfix….
The configuration option is “message_size_limit” and by default is set to 10240000 bytes which is roughly 10MB. You can see what setting your postfix is by running:
postconf message_size_limit
For the default setting, you’ll see this:
message_size_limit = 10240000
To change the setting to some other value, open the main.cf file in your favourite text editor
vi /etc/postfix/main.cf
either edit or add the following line…
message_size_limit = 20480000
Above example is 20MB.
Then reload postfix:
service postfix reload
and your setting will take effect.