I would like your input on the following matter:

1. Users should be able to establish mailboxes on the server by utilizing the web interface.
2. The implementation of mail filtering software.

Any information about who accomplished this would be greatly appreciated.

Thank you for your time and consideration!

1. I would suggest utilizing qmail + vmailmgr, which enables specific customization options such as setting redirect rules, disk quotas, maximum letter sizes, and the maximum number of letters per mailbox.

2. To prevent virus infiltration, I recommend using qmail-scanner + Sophos Sweep (which is a free program). This combination will effectively eliminate all viruses. Meanwhile, SpamAssassin can act as a spam filter, and its overall performance has been satisfactory.

Mailbird provides a simple and intuitive interface to navigate through the application. It is an excellent alternative for those who find Outlook's interface difficult to use. While Mailbird may appear to have fewer features than Outlook, its features are actually more powerful and are available without cluttering the application.

Gmail is a web client, which allows users to access their email from anywhere without having to install a separate application. However, it has some disadvantages, including the inability to read old emails without network access and fewer features compared to an application.

eM Client offers a minimalistic design that is easy to navigate without being overwhelmed by unnecessary features. It has a built-in calendar, instant messaging application, and supports major mailboxes like Gmail, Outlook, and Yahoo.

Thunderbird is well-known for its advanced customization options and security system, making it an excellent alternative to Outlook. It has plenty of standard features and add-ons that allow users to customize it to their needs.

Spark is a collaborative tool that allows employees to work together in real-time. It has mobile apps for iOS and Android, along with a desktop version for macOS. Spark syncs with Outlook, iCloud, Google, Yahoo, Exchange, and IMAP mail accounts, and has several useful features such as smart mailbox, pinning important emails, and customizable signatures. The Premium plan offers the best collaboration tools, making it ideal for startups, small/medium companies, large companies, managers, team collaboration, and task management.