Email, Messaging, & Video Calls Email How to Access IMAP Inbox Offline in Mozilla Thunderbird By Heinz Tschabitscher Writer A former freelance contributor who has reviewed hundreds of email programs and services since 1997. our editorial process Heinz Tschabitscher Updated November 27, 2019 PM Images / Getty Images Email Yahoo! Mail Gmail Tweet Share Email IMAP is flexible, versatile, swift, and cool. IMAP is good. But to access your mail from anywhere on the server, you need a connection to that server from somewhere. If you leave to an area without net access and want to take your mail with you, what should you do? If you tell Mozilla Thunderbird, Mozilla SeaMonkey, or Netscape to make your IMAP account inbox available offline, all messages will automatically be downloaded to your computer and you can read them or write replies without being connected. Access Your IMAP Email Inbox Offline with Mozilla Thunderbird To set up offline access to your IMAP email inbox in Mozilla Thunderbird: Select Tools > Account Settings... from the menu in Mozilla Thunderbird.Select the Synchronization & Storage category for the desired IMAP account.Make sure Keep messages for this account on this computer is checked.Click Advanced….Make sure Download is checked for the Inbox folder.You can select any additional folders you want available offline, too.Click OK.Click OK again. Access Your IMAP Email Inbox Offline with Mozilla SeaMonkey or Netscape To access your IMAP email inbox offline with Mozilla SeaMonkey or Netscape: Select Tools > Account Settings... from the menu.In Netscape and Mozilla SeaMonkey, select Edit > Mail & Newsgroup Account Settings...Go to the desired IMAP account.Select the Synchronization & Storage (or Offline & Disk Space) category.Make sure Make the messages in my Inbox available when I am working offline is checked.Click OK. Go Offline in Mozilla Thunderbird, Mozilla SeaMonkey or Netscape Now, to go offline: Select File > Offline > Download/Sync Now... from the menu.Make sure Mail messages is selected under Download and/or sync the following:Also check Work offline once download and/or sync is complete.Click OK. To go back online: Click the online/offline icon in the lower right corner of the main window.Alternatively, select File > Offline > Work Offline from the menu.