/var/spool/smail/retry/smtp

[Gerry Jensen <gerry@blue.intele.net>]

Today, while perusing through our system, I came across 24 files in 
a /var/spool/smail/retry/smtp directory.  The files are named after 
various Internet hosts, and contain short error messages, such as:

---
148 transport smtp: connect: Connection refused

172 transport smtp: no connection to remote SMTP server: 499 read error 
from remote SMTP process

172 transport smtp: no connection to remote SMTP server: 421 
bcars568: PP cannot resolve your address. '204.250.31.220' (Help from:  
postmaster@bnr.ca)
---

I believe the source of most (possibly all) these messages is because our
Internet service provider does not have reverse name lookup set up
correctly for our IP address. 

My questions are: 

1 - Does this mean that for each of these messages, an email message was
lost, or does smail try an alternate path until the mail was sent
successfully? 

2 - Do these files serve any purpose now (such as does smail avoid 
sending mail through these hosts in the future?), or may I delete them?

Thanks,

Gerry
gerry@blue.intele.net

PS: If these files may be deleted, perhaps it would be a good idea to
include in a cron file within the smail package that periodically deletes
old files from this directory.