The MailTags component integrates tags with search, rules, smart mailboxes, Calendar, Reminders, and project-management software for near-perfect and semiautomatic custom email organization. MailSuite includes Act-On, a Mail plug-in that saves time with keyboard shortcuts. You can set up shortcuts for labeling, moving, or redirecting messages. Mail Perspectives offers a customizable compact window design that keeps your most important email visible but not in your face as you work. With SigPro, you create a signature one time and then customize it by calling a script. MailSuite costs $60. It is compatible with macOS Big Sur, macOS Catalina (10.15), macOS Mojave (10.14), macOS High Sierra (10.13), and macOS Sierra (10.12). With MailButler, you can make templates from your frequently sent email messages to save time and generate follow-up reminders so that you don’t forget important opportunities. Mailbutler offers a 14-day free trial and three plans, one of which is free with limitations. MailButler works with macOS Big Sur, macOS Catalina (10.15), macOS Mojave (10.14), macOS High Sierra (10.13), and macOS Sierra (10.12). A free 15,000-email archive version is available, as are paid upgrades for bulk users. MailSteward Lite costs $24.95 and includes archiving for up to 100,000 messages. Two additional plans are available for power and enterprise users. MailSteward is compatible with Mail in macOS Big Sur, macOS Catalina (10.15), macOS Mojave (10.14), macOS High Sierra (10.13), and macOS Sierra (10.12). SpamSieve features include:

Color coding that indicates the spam level of each message.Customizable safelist and blocklist.Runs on a Mac and keeps spam off iPhone and iPad.Integrates with the macOS Contacts app.Notifies you only for the receipt of non-spam emails.

A free trial is available. The paid version is $30. Compatible with macOS Big Sur, macOS Catalina (10.15), macOS Mojave (10.14), macOS High Sierra (10.13), and macOS Sierra (10.12). A 7-day free trial is available. The cost for a basic Business plan is $30 per month per person, with annual discounts and Business Premium and Business Enterprise plans. Mail Designer 365 works on macOS Big Sur, macOS Catalina (10.15), macOS Mojave (10.14), macOS High Sierra (10.13), and macOS Sierra (10.12). The free GPG Suite download includes a 30-day trial of GPG Mail. After 30 days, GPG Mail costs $23.90. GPG Suite is compatible with macOS Catalina (10.15), macOS Mojave (10.14), and macOS High Sierra (10.13). MsgFiler is available at the Mac App Store for OS X. For macOS, go to the developer’s website, download two files, and follow the instructions to install the plug-in. The cost of MsgFiler is $9.99. MsgFiler works with macOS Big Sur, macOS Catalina (10.15), macOS Mojave (10.14), macOS High Sierra (10.13), and macOS Sierra (10.12). MailHub is compatible with Mail in macOS Mojave (10.14), macOS High Sierra (10.13), and macOS Sierra (10.12) MailHub offers a 30-day unrestricted free trial. The price is $19 for a single user, $49 for a five-user license, and $89 for a 10-user business account. Letter Opener offers a 14-day free trial and costs $29.99 per year. Letter Opener is compatible with macOS Big Sur, macOS Catalina (10.15), macOS Mojave (10.14), macOS High Sierra (10.13), and macOS Sierra (10.12). Email Archiver Pro Personal edition costs $39.99. Business and enterprise plans are also available. Email Archiver Pro is compatible with macOS Mojave (10.14), macOS High Sierra (10.13), and macOS Sierra (10.12). Ofaco works with Mail in macOS Big Sur, macOS Mojave (10.14), macOS High Sierra (10.13), and macOS Sierra (10.12). The Ofaco plug-in is free. Donations are accepted.