Mail

Docs

• Email explained
• Postfix documentation
• A Deep Dive into Email Deliverability in 2024

Servers

• QMail
• Sendmail
• Exim
• Postfix
• Exchange

Tools

• http://mxtoolbox.com/
• Swaks - Swiss Army Knife for SMTP
• mail-tester.com

Blacklists

• RBL
• My email blacklist

Mailing lists

• Ezmlm
• Majordomo
• Mailman
• Pommo
• phplist

Related services and tools

• IMAP
• Fetchmail
• Procmail
• formail
• bayes spamfiltering
• SRS
• swak
• sendEmail: commandline tool for sending test mails

Filters

• Amavis
• ClamAV
• Spamfilters

Webmail

• Horde
• Squirrelmail
• Roundcube
• Rainloop

SMTP servers of ISPs

• SMTP servers in Nederland

Tips&Tricks

Send maildir mails to a remote server

without damaging the From and Subject etc.

cat somemail | formail -i "To: new@address.com" | sendmail -t

script for testing mailservers

sendEmail

send mail from command line with sender address

echo text | mail -s testsubject -r fromuser@example.com touser@example.com

Test submission

See https://halon.io/blog/how-to-test-smtp-servers-using-the-command-line/ Encode using

echo -n whatever | base64

openssl s_client -starttls smtp -crlf -connect server:587
ehlo your.host
auth login
base64 encoded username
base64 encoded password

FAQ

451 4.7.500 Server busy. Please try again later

Try rate limiting your outgoing mail. Most likely you need to check/add SPF/DKIM/DMARC