SMTP

Troubleshooting and performance tuning

1. swaks - swiss army knife for SMTP

2. jmeter-mail - load testing and performance measurement application

3. postal - SMTP benchmark

4. xstress - SMTP stress tester

Online tools

• mxtoolbox

• email verification (paid service)

• send test e-mail to check-auth@verifier.port25.com

MTAs

• Exim4

• Postfix

• Sendmail

• qmail

• e-mail marketing and MTAs

Email authentication or best practices

• SenderID

• DKIM

• SPF

• SRS

• DMARC