Mail Proxy Server using NGINX

Nginx is open source software for web serving, reverse proxying, caching, load balancing, media streaming, and more. NGINX is highly scalable as well, meaning that its service grows along with its clients traffic.

NGINX can proxy IMAP, POP3 and SMTP protocols to one of the upstream mail servers that host mail accounts and thus can be used as a single endpoint for email clients. This may bring in a number of benefits, such as

Easy scaling the number of mail servers
Choosing a mail server basing on different rules, for example, choosing the nearest server basing on a clients IP address
Distributing the load among email servers

Mail Proxy Features:

POP3/SMTP/IMAP over SSL/TLS
Optimised SSL/TLS for mail Proxy - Faster & more secure
Load balance mail server traffic
Load balancer in-band health checks
Reverse proxy support
Test your TCP mail upstream servers
Keep-alive and pipelined connections support
Access control based
Response rate limiting
HTTP authentication (LDAP)
STARTTLS support
TLS/SSL with SNI and OCSP stapling support, via OpenSSL

NGINX can also be used as a cache for static and dynamic content. Increasing the speed for users access.

Disclaimer: This solution is built using Nginx, Inc. and its contributors, an opensource software. This solution is Licensed under the 2-clause BSD license.