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SSL encryption wrapper

'Stunnel' works as an SSL encryption wrapper between a remote client and a local (inetd-startable) or remote server. It adds SSL functionality to commonly used inetd daemons like POP2, POP3, and IMAP servers without any changes in the programs' code. It will negotiate an SSL connection using the OpenSSL or SSLeay libraries. It calls the underlying crypto libraries, so stunnel supports whatever cryptographic algorithms you compiled into your crypto package.


See for a complete list of documentation


Download version 5.39 (stable)
released on 1 January 2017

Paid technical support available from


Related Projects


LicenseVerified byVerified onNotes
License:GPLv2 with exceptionJanet Casey29 July 2002

Leaders and contributors

Michal Trojnara Maintainer
Adam Hernik Contributor
Brian Hatch Contributor
Dirk O. Siebnich Contributor
Pawel Krawczyk Contributor

Resources and communication

AudienceResource typeURI

Software prerequisites

Required to buildOpenSSL
Weak prerequisitetcp wrappers

This entry (in part or in whole) was last reviewed on 11 January 2017.


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