This article describes the major changes that are visible to users in Thunderbird version 45.0. Full details of all the changes can be found in the Thunderbird 38 release notes (link missing). __TOC__ =Mail Composition= Various improvements have been made to mail composition. The sender name (From) can now be [https://bugzilla.mozilla.org/show_bug.cgi?id=87987 edited in-situe] to allow for one-off adjustments. When using more than one spell check dictionary, the dictionary can now be selected while entering the message subject. There is also a [https://bugzilla.mozilla.org/show_bug.cgi?id=368915 language indicator] showing the selected dictionary. The font size selection has changed, there is now a [https://bugzilla.mozilla.org/show_bug.cgi?id=769604 button for size selection] on the editing toolbar and the "Smaller/Larger font size" buttons now change the size to the next available font discrete size. The Thunderbird composition window now functions more like a word processor in that pressing the "Enter" key inserts a new paragraph, pressing "Shift+Enter" inserts a new line. This new behaviour can be switched off through the {menu Tools > Options > Composition} menu. =Mail Delivery Format= Previously Thunderbird sent mail as plain text if no "rich text" elements were used in the message and the recipient wasn't marked as preferring HTML e-mail in the address book. This automatic "downgrade" can not be disabled in the {menu Tools > Options > Composition, Send Options} menu. =Chinese, Japanese and Korean mail= When sending e-mail which was composed using Chinese, Japanese or Korean characters, unwanted extra spaces were inserted within the text. This has been corrected and mail will be sent and received exactly as it was composed. Japanese mail now fully supports RFC 1468 and RFC 3676. =Remote Content Exceptions= By default, Thunderbird does not display images embedded in HTML messages that are not sent with the message but need to be loaded from a web site. This protects the users against tracking. The menu to select sites for which remote content will be loaded as been improved. Embedded images will now also be displayed [https://bugzilla.mozilla.org/show_bug.cgi?id=1251408 in replies or forwarded messages] if they were displayed in the original message. (Note: Due to internal changes, remote content exceptions based on the senders e-mail address are not migrated from Thunderbird 38.) =Address Book Export= The address book can now be [https://bugzilla.mozilla.org/show_bug.cgi?id=117236 exported as UTF-8] and [https://bugzilla.mozilla.org/show_bug.cgi?id=1246703 all address books] can be exported at the same time. =Message List and Message Pane= The headings in the message pane now show a [https://bugzilla.mozilla.org/show_bug.cgi?id=36489 "Correspondents" column] by default instead of the "From" and "Recipient" column. Existing folders will be upgraded to the new column, unless this upgrade is [https://bugzilla.mozilla.org/show_bug.cgi?id=1152706 switched off]. [https://bugzilla.mozilla.org/show_bug.cgi?id=232021 Name and e-mail address] can now be copied from a message displayed in the message pane.

This article describes the major changes that are visible to users in Thunderbird version 45.0. Full details of all the changes can be found in the Thunderbird 38 release notes (link missing).

Mail Composition

Various improvements have been made to mail composition. The sender name (From) can now be edited in-situe to allow for one-off adjustments. When using more than one spell check dictionary, the dictionary can now be selected while entering the message subject. There is also a language indicator showing the selected dictionary. The font size selection has changed, there is now a button for size selection on the editing toolbar and the "Smaller/Larger font size" buttons now change the size to the next available font discrete size. The Thunderbird composition window now functions more like a word processor in that pressing the "Enter" key inserts a new paragraph, pressing "Shift+Enter" inserts a new line. This new behaviour can be switched off through the Tools > Options > Composition menu.

Mail Delivery Format

Previously Thunderbird sent mail as plain text if no "rich text" elements were used in the message and the recipient wasn't marked as preferring HTML e-mail in the address book. This automatic "downgrade" can not be disabled in the Tools > Options > Composition, Send Options menu.

Chinese, Japanese and Korean mail

When sending e-mail which was composed using Chinese, Japanese or Korean characters, unwanted extra spaces were inserted within the text. This has been corrected and mail will be sent and received exactly as it was composed. Japanese mail now fully supports RFC 1468 and RFC 3676.

Remote Content Exceptions

By default, Thunderbird does not display images embedded in HTML messages that are not sent with the message but need to be loaded from a web site. This protects the users against tracking. The menu to select sites for which remote content will be loaded as been improved. Embedded images will now also be displayed in replies or forwarded messages if they were displayed in the original message. (Note: Due to internal changes, remote content exceptions based on the senders e-mail address are not migrated from Thunderbird 38.)

Address Book Export

The address book can now be exported as UTF-8 and all address books can be exported at the same time.

Message List and Message Pane

The headings in the message pane now show a "Correspondents" column by default instead of the "From" and "Recipient" column. Existing folders will be upgraded to the new column, unless this upgrade is switched off. Name and e-mail address can now be copied from a message displayed in the message pane.