The folder list on your Fastmail account may display differently on your local mail client to how it appears on the web, especially if special characters such as . or ^ are used.
This is because your third party email client is accessing the raw IMAP data directly from the server. Due to a variety of technical reasons, we store data a particular way on the server, and then display it in a way that makes sense to the user. Some email clients do not do this conversion, and instead display the raw data from the server.
These raw folder names also need to be used in Sieve scripts, as Sieve doesn't perform the folder name translations either.
Effect on dot (.) characters in folder names
If you create a folder called i.really.like.dots in the Fastmail web interface or our mobile app, you will see a folder of that name show up in the web interface.
However, it will show up as i^really^like^dots in some IMAP clients. This is the format you'd need to use in Sieve.
Some IMAP clients, like Mac Mail, handle dots differently. If you create a folder in Mac Mail called a.dot, Mac Mail will make one folder called a with a subfolder named dot. These two folders will also appear in the Fastmail web interface.
Effect of caret (^) characters in folder names
The Fastmail web interface prevents you from creating a folder name with a ^ in it, as this is a special reserved character.
If you create a folder with carets in it via an IMAP client, Fastmail will be unable to display it in the web interface. Many clients will also refuse to save it.
Unable to see shared folders
Many mail clients can't handle the special characters Fastmail uses to indicate shared folders. While they will always be displayed in the web interface and our mobile app, not all IMAP clients display them correctly.
Mail clients that can display shared folders
- Fastmail web interface
- Fastmail mobile app
- iPhone Mail app
- Thunderbird
Mail clients that can't display shared folders
- emClient
- Windows Mail