Thunderbird 60.3.1

Thunderbird

Thunderbird is a free, open-source, cross-platform application for managing email and news feeds. It is a local (rather than a web-based) email application that is powerful yet easy-to-use. Thunderbird is developed, tested, translated and supported by the folks at Mozilla Corporation and by a group of dedicated volunteers. Thunderbird gives you control and ownership over your email. There are lots of add-ons available for Thunderbird that enable you to extend and customize your email experience.

Thunderbird gives you IMAP/POP support, a built-in RSS reader, support for HTML mail, powerful quick search, saved search folders, advanced message filtering, message grouping, labels, return receipts, smart address book LDAP address completion, import tools, and the ability to manage multiple e-mail and newsgroup accounts.

What's fixed in Thunderbird 60.3.1:

Double-clicking on a word in the Write window sometimes launched the Advanced Property Editor or Link Properties dialog
Cookie removal (not working since Thunderbird version 52)
"Download rest of message" not working if global inbox was used
Encoding problems for users (especially in Poland) when a file was sent via a folder using "Sent to > Mail recipient" due to a problem in the Thunderbird MAPI interface
According to RFC 4616 and RFC 5721, passwords containing non-ASCII characters are encoded using UTF-8 which can lead to problems with non-compliant providers, for example office365.com. The SMTP LOGIN and POP3 USER/PASS authentication methods are now using a Latin-1 encoding again to work around this issue.
Shutdown crash/hang after entering an empty IMAP password

Known Issues:

Under some circumstances Thunderbird on Mac will send attachments using the so-called AppleDouble format which can lead to problems with mail servers and recipients
CalDav access to some servers not working. Workaround: Set preference network.cookie.same-site.enabled to false.
Chat: Twitter not working due to API changes at Twitter.com (solution forthcoming)