SMTP Codes
Welcome to smtp.codes, your source for everything about where and how SMTP codes are used.
Codes
Providers
- Amazon Simple Email Service
- AT&T
- Barracuda
- Cisco
- Comcast
- Email Security.cloud
- Exchange Online Protection
- FireEye
- Free
- GMX
- GoDaddy
- HEY
- Hostpoint
- iCloud
- ImprovMX
- Infomaniak
- Mail.ru
- Mimecast
- MXroute
- Orange
- Outlook
- Proofpoint
- Proton Mail
- Rackspace
- Rambler
- Trend Micro
- Web.de
- Yahoo Inc
- Yandex
- ZeroSpam
- Zoho