F*EX use case: BIGMAIL

Some users are overcharged in using two different tools for one task:
They want to use ONLY their known mail program no matter how big their e-mail with attachments is.

42 years after invention of the CD it is still not possible to send it by e-mail. Not mentioning DVDs...

You can set up a F*EX enabled MTA which accepts e-mails of any size. The e-mails will be scanned for big attachments and if they are bigger than a specified size (default: 10 MB), they will get deattached, stored on the F*EX server and inside the e-mail replaced with the download link. Example:

  112 MB attachment saved as:

  https://fex.belwue.de/fop/FfuPU17x/DWH.zip

  Attention: URL will expire after 10 days!

F*EX enabled postfix with fexmail

Operation mode: the postfix mail relay pipes incoming smtp e-mail from the MUA to the fexmail script which disassembles the e-mail in its MIME components and sends the attachments via fexsend to the fexserver (one needs an UNIX fexmail user and a F*EX fexmail user). The fexmail script then reassembles the e-mail using the download URL(s) provided by the fexserver and reinjects it into the mail relay.

Setup details:

create a F*EX user fexmail@YOURDOMAIN on your fexserver (with /home/fex/bin/fac)
set up a postfix mail relay which accepts mails from your clients (may be on another host than your fexserver) and:
- install the Perl module MIME::Words (for example with: cpan MIME::Words)
- create a UNIX user fexmail
- install fexsend and fexmail in /home/fexmail/
- run as user fexmail: /home/fexmail/fexsend -I
- add to /etc/postfix/master.cf :
```
	25      inet  n       -       -       -       -       smtpd
	  -o content_filter=filter:dummy

	filter    unix  -       n       n       -       10      pipe
	  flags=Rq user=fexmail null_sender=
	  argv=/home/fexmail/fexmail -f ${sender} -- ${recipient}
       
```
- set in /etc/postfix/main.cf :
```
	message_size_limit = 0
       
```
- restart postfix
tell your users to configure their MUAs to use the new smtp mail relay
hint: instead of smtp port 25 you can alternativly use port 587 in /etc/postfix/master.cf to separate normal mail relaying from fexmail