LibreOffice - Free office suite, open source, and compatible with .doc, .docx, .xls, .xlsx, .ppt, .pptx files. Updated regularly – download for free. Originally based on OpenOffice.org.
MailStore - MailStore Home - A 100% free single-private-user desktop solution
Microsoft 365 - Boost your productivity with reliable access anywhere with services like email, calendar, file sharing, meetings, instant messaging, and Office Online
MailSteward - MailSteward : The Ultimate E-mail Manager for Mac OS X
ONLYOFFICE - ONLYOFFICE is a complete office and productivity suite.
Gmvault - Backup the emails in your Gmail account.