BaGoMa backs up and restores the contents of a GMail account. It can restore all the labels (folder structure), as well as the flags (seen/read, flagged) of a message. It supports the use of any character in labels, including non-ASCII characters and "/" (the label hierarchy delimiter). BaGoMa is tuned to work specifically with GMail. Each message is only downloaded and saved once. Backup solutions that are designed to work with regular IMAP accounts will download each message multiple times (once per label) when used to back up a GMail account. This can significantly increase the bandwidth requirements and the amount of storage required for backup. Additionally, a faithful restoration of your GMail account might not be possible from such a backup.
Spampig DnsblCheck takes the IP address of a mail server and looks it up in common blacklists and whitelists. The program tests against the major block lists from Spamhaus, SORBS, Spamcop, Barracuda, UCEProtect, and others. In addition to blacklists, it also checks against IP address and domain name whitelists and even checks PTR record integrity. The program returns results quickly, typically in less than a few seconds. If you don't get results quickly, it indicates you may have DNS problems and knowing this can also be useful. This application can be useful to spam fighters and email users who are struggling to find out why their messages are being blocked.
SMTPUtils is a tool to secure mail servers, through testing or analysis, which provides the service manager or staff of computer security a summary of its implementation. It currently supports: resolution by MX record, checking for open relays, testing the perimeter antivirus system, testing the anti-spam system, performance testing, obtaining information, checking for DNSBL, SPF greylisting autodetection, and ping support.
E-MailRelay is a simple SMTP store-and-forward mail transport agent (MTA). It runs as an SMTP server, storing incoming e-mail in a local spool directory, and then forwarding the stored messages to a downstream SMTP server on request. It can also run as a proxy server, forwarding (and optionally pre-processing) incoming e-mail as soon as it is received. It does not do any message routing other than to a local postmaster. Because of its simplicity E-MailRelay is extremely easy to configure, typically requiring only the address of the downstream SMTP server to be put on the commandline.