Luke Dudney wrote: > There are lightweight SMTP clients that can be used as drop-in > sendmail(1) replacements by speaking directly to a remote SMTP server > instead of dropping the message in the local queue directory. One that > I've used is mini_sendmail > (http://www.acme.com/software/mini_sendmail/), though this was a while > ago but I seem to recall having some success with it. > > Others have mentioned the trade-off between the additional complexity > of maintaining an MTA on each system and the fault-tolerance such a > setup provides, however, you can achieve similar levels of fault > tolerance by implementing redundancy on your relay server system(s). I > guess it's up to you to figure out what's appropriate to your > environment. it's not a redundancy issue. it's a queue issue. when cron sends mail and if the sendmail command fails, cron can't do anything (it won't queue mail and retry later). That said, one can write a script (perl comes to mind) or program that: - replaces sendmail - tries to send, and if it fails saves the message in a queue - runs periodically (from cron for example) to check the queue but I am not convinced that setting this up on every machine would be easier than configuring postfix or sendmail as a "null client".