Sympa

Sympa is an excellent mailing list software that is scalable and highly customizable. It boasts the ability to handle large lists with up to 780,000 subscribers, which is impressive. One of its most significant strengths is the complete web interface it provides for both users and administrators, making usage and management quite easy.

With Sympa, internationalization is possible, allowing sites to cater to a broad audience. The mailing list software is also highly customizable, and sites can tailor their web and mail templates, authentication backends, and authorization scenarios to their liking.

Dynamic mailing lists are not left out. Sympa can use multiple backends such as LDAP, SQL, files, lists or others. Thus, users can enjoy the flexibility of choosing the backend that works best for them.

Lastly, Sympa is the only S/MIME enabled mailing list software. It provides both authentication and encryption, making it one of the most secure mailing list software available. With all these features in one software package, Sympa is undoubtedly a great choice for anyone looking for a mailing list software.