Sisimai is a library that decodes complex and diverse bounce emails and outputs the results of the delivery failure, such as the reason for the bounce and the recipient email address, in structured data. It is also possible to output in JSON format.
Sisimai is a library to decode bounce mails for UNIX mbox format files and those in Maildir/ directories.
Sisimai can decode 34 bounce reasons, including common errors such as "userunknown", "mailboxfull", and "rejected".
The data of bounce emails decoded by Sisimai is structured and can also be output in JSON format.
Sisimai can decode bounce emails from open-source MTAs, commercial MTAs, email appliances, and well-known email services.
In the summer of 2014, the Perl version of Sisimai(pronounced as 'shi-shi-mai') was developed to solve several critical problems with the decoding accuracy of bounceHammer, including: Inability to decode multiple bounces in a single email, Large number of dependent modules, some of which are no longer maintained, Inability to work with Perl 5.16 or later.
Sisimai Sisimai is now about 2.2 times faster than bounceHammer and has twice the decoding accuracy. The Ruby version of Sisimai was released on February 3, 2016.
On February 2, 2024, the 10th anniversary of the release of Sisimai, Sisimai v5.0.0 was released. This version can detect modern bounces, including those caused by domain authentication (SPF, DKIM, DMARC) errors and reputation issues.
Analytical Precision Ratio
The Speed Of Decoding 1000 Emails
Detectable Bounce Reasons
The Number Of MTA/MSP Modules
Dependent External Modules
Commercial MTA Modules
External Modules Required
Sisimai can run on any OS where Perl or Ruby works, such as *BSD, macOS, and Linux. Sisimai 4.22.5 and later may run with ActivePerl on Windows. .
Sisimai is an open-source library licensed under the two-clause BSD license, so anyone can use it freely. However, Cubicroot Corporation Limited, the developer of Sisimai, offers products and services to support the following: