My bitdefender is not updating
While add-ons may operate in this release, note that support for add-ons will be eventually discontinued.
Postbox is based on Mozilla code, and as of Firefox Quantum, Mozilla has discontinued support for add-ons.
It learns what spam looks like and what good messages look like, using "Bayesian" analysis to improve its filtering and blocklist (which can be viewed and edited, if necessary).
Spam Sieve 2.9.30 is priced at for mail clients running in OS X 10.7 and up, with a free trial available.
(We recommend removing Adobe Flash from your systems because of its constant stream of security flaws and exploitation.
Adobe has announced its future termination.) "A critical vulnerability (CVE-2018-4878) exists in Adobe Flash Player 22.214.171.124 and earlier versions.
Hands Off 3.2.6 is priced at .99 (one user) for OS X 10.9 and up, with a free demo version available.Features include an address book; custom account groups; indexing of all message contents, including images and links; customizable tags; viewing by topic or thread; archiving; phishing and malware protection; quick filtering (e.g."Today" or "Not Replied"); gesture support; a favorites bar; canned responses; to-do tagging (flags); summarized replies; subject editing; favorite contacts; add-ons (including Cloud File Sharing for large files, calendar support, encryption and others); Spam Sieve support and more.A recent update brought new capabilities in conjunction with mac OS 10.13 High Sierra's new APFS file system, promising "Time Machine-like restoration from bootable APFS copies." Super Duper 3.1.4 is priced at .95 for OS X 10.10 and up.(Older versions support systems as early as Mac OS X 10.2.) In trial mode, prior to purchase, Super Duper can clone a drive but lacks Smart Copy and other features when unregistered.