Postbox's Default Behaviors
When you click on a folder, Postbox will first download all of the message headers for that folder. The headers contain information that populates the message list, such as sender, subject, date, etc. However, Postbox will not download the message bodies (the message content) until you click and/or view a message.
This approach allows you to receive and review the message list without first having to wait for the message bodies to download, and this is how most email clients work.
The downside is that if you are disconnected from the network (for example, on a plane), you may not have access to your message bodies, even for messages that you can see in the message list.
Postbox will check for new messages within the Inbox only. Thus, if you move messages to a folder using a different computer or your phone, Postbox will not download the message headers or bodies until you click on the folder.
This approach ensures that the server is not hit with update requests for each folder every time you check for messages, as this degrades performance and bog down your mail servers.
Now, here's the important part... When Postbox detects that your computer is idle, it will download your messages as part of the indexing process. The indexer will step through each folder to download headers and message bodies, and will then index them to make searches fast and accurate.
Thus, the easiest way to ensure that Postbox is in sync with your mail servers is to simply leave Postbox running during meetings, lunch, or overnight. Alternatively, you can go to the Tools menu and select Indexing > Index All Folders, and this will download and index all of your messages.
Changing the Postbox Defaults
With this in mind, there are a few changes that you can make to more aggressively sync your messages.
For IMAP users, you can configure Postbox to check folders other than the inbox for new mail. This is particularly useful if you have server-side filters that move messages into other folders.
Right-click on the folder in your folder tree, then select Properties... from the context menu. Then select:
[X] Check this folder for new messages
To download all message headers or message bodies, navigate to Preferences | Options > Advanced > General and select:
[X] Download all message headers
[X] Download all message bodies
Finally, if you're having trouble syncing messages across devices, navigate to Preferences | Options > Advanced > General and select:
[X] IMAP Expunge
Setting Postbox up for Offline Use
One of the most convenient features of using a mail client like Postbox is the ability to be productive while offline. Even without an internet connection, you can still use Postbox to read, respond to, and organize messages. Once you reconnect, Postbox will send any messages in your Unsent folder and update any changes that were made to your accounts.
Here's an what you can expect while working offline:
- By default, every message in your Inbox(es) is available for offline use
- You can configure any additional IMAP folders to be available offline
- Any messages composed (new, replied, or forwarded) will be placed in the Unsent folder when you click the Send button and stay there until the connection is restored
You can configure each account's offline settings by going to:
Mac: Preferences | Accounts | <your account> | Local Storage
Windows: Options | Accounts | <your account> | Local Storage
Here, you can decide whether your Inbox will be available offline and configure whether new folders created in the account will be available offline as well. In addition, clicking the Select folders for offline use... button will let you place a checkmark next to any additional folders that you would like to make available.
(In order to configure offline settings, make sure the account, and not an account group, is selected.)
If you're anticipating working offline, you can tell Postbox to download/sync changes to all messages in your configured email folders and newsgroups. In addition, you can send all unsent messages, and have Postbox go into Work Offline mode once the process is complete.
To download/sync your accounts in Postbox, go to the File menu and select Offline > Download/Sync Now...
(In order to download/sync your account, make sure the account, and not an account group, is selected.)
Manually Working Offline
Postbox will automatically detect whether you have an internet connection, and configure itself accordingly. However, you can tell Postbox to "Work Offline" if you don't want to make any connections with your mail servers to download and sync your messages. To do this go to File | Offline | Work Offline, or click the lightning symbol at the bottom left corner of the Postbox window.