nginx IMAP proxy

nginx-compilation-and-configuration

nginx SMTP proxy

nginx POP proxy

nginx mail proxy

Brief nginx compilation and configuration guide with fcgiwrap, mail imap/pop/smtp proxy module, etc. nginx IMAP proxy https://pluslab.net/blog/nginx-imap-proxy/

Need to compile nginx because the default installation is not good enough? This guild could be helpful.

Connection diagram:

       /-----------------\
USER-->| NGINX server    |
       | protocol & port:|
       |-----------------|            
       |   smtp     25    \
       |            465    > 127.0.0.1:22025 --> stunnel-> SMTP ssl server (port 465)
       |            587   /
       |-----------------|            
       |   pop3     110   \
       |            995    > 127.0.0.1:22143 --> stunnel-> IMAP ssl server (port 993)
       |                  /
       |-----------------|            
       |   imap      143  \
       |             993   > 127.0.0.1:22110 --> stunnel-> POP3 ssl server (port 995)
       |                  /
       |-----------------|
       \-----------------/

   graph TD
    B[user mail client]
    B --> C{Nginx server <br> protocol/port}
    C -->|imap port 143/993| D[stunnel server <br> 127.0.0.1:22143] --> H[imap ssl server <br> imaps.mydomain.com:993]
    C -->|pop3 port 110/995| E[stunnel server <br> 127.0.0.1:22110] --> I[pop3 ssl server <br> pop3s.mydomain.com:995]
    C -->|smtp port 25/465/587| F[stunnel server <br> 127.0.0.1:22025] --> J[smtp ssl server <br> smtp.mydomain.com:465]

OS:

• CentOS
• Ubuntu

Configuration:

• fcgiwrapper configuration (optional)
• nginx mail module (for imap, pop, and smtp proxy)

Auth methods (use any):

• Built in nginx authentication
• Perl CGI simple authentication (requires fcgiwrapper)
• Bash script with netcat simple example

Bonus:

• stunnel - making SSL connection to actual mail servers
• Dummy SSL installation
• Let's encrypt free SSL installation

Not (yet) included:

• php installation