1 of the things we started working on during pan. was FTP2SMTP ( F2S ), in a nutshell you send a data. stru. in a file which can contain 'attachments' etc. to a FTP server and the FTP server has a SMTP server that sends the email. As this is happening on the server(s) u have much greater control.
This probably sounds really weird, but it means 4us lots of issues evaporate, like changing the From field in an email on a client we have been doing this depending on who the email is sent 2 'Recipient', so with F2S it is text in the file, no need to mod. the client and add a DB to manage the changing of these fields - job done
Plus if your customers have static IPV4's you can have much improved authentication on FTP server using WAN fingerprinting.
There r a lot more positives, but I cant put them here in an open forum.
Has anyone used FTP in a similar manner eg. front end other protocols because FTP outbound on a client doesn't generate 'issues' with client sec. soft. due to programmatic implementation ?
BTW - These r legacy apps. 20+ YO and we r never going to re-write to use HTTP as customers luv the small screen real estate experience popping out of the tray, not BIG web pages