FolderNotFound exception

[ekalchev]

var personalNamespace = imapConnection.PersonalNamespaces[0];
imapConnection.GetFolder(personalNamespace);

This code throws FolderNotFound exception. I thought I am doing something wrong and tried a workaround but this

imapConnection.GetFolders(personalNamespace, StatusItems.None, false);

also throws an FolderNotFound exception

I am using Protonmail bridge to connect to protonmail imap server.

Connected to imap://127.0.0.1:1143/?starttls=when-available
S: * OK [CAPABILITY IMAP4rev1 STARTTLS AUTH=PLAIN AUTH=LOGIN ID APPENDLIMIT] IMAP4rev1 Service Ready
C: A00000000 STARTTLS
S: A00000000 OK Begin TLS negotiation now
C: A00000001 CAPABILITY
S: * CAPABILITY IMAP4rev1 AUTH=PLAIN AUTH=LOGIN ID XSTOP APPENDLIMIT
S: * CAPABILITY IMAP4rev1 AUTH=PLAIN AUTH=LOGIN ID XSTOP APPENDLIMIT
S: A00000001 OK CAPABILITY completed
C: A00000002 AUTHENTICATE PLAIN
S: +
C: ?????????
S: A00000002 OK [CAPABILITY IMAP4rev1 IDLE MOVE SPECIAL-USE ID XSTOP QUOTA APPENDLIMIT=26214400] AUTHENTICATE completed
C: A00000003 LIST "" ""
S: * LIST (\Noselect) "/" "/"
S: A00000003 OK LIST completed
C: A00000004 LIST "" "INBOX"
S: * LIST (\Noinferiors) "/" "INBOX"
S: A00000004 OK LIST completed
C: A00000005 LIST (SPECIAL-USE) "" "*"
S: A00000005 BAD Reference name must be a string

[jstedfast]

Can you research what the correct command should be? Looks like a bug in ProtonMail, but I could be wrong.

[ekalchev]

I can see Outlook and Em Client work correctly with protonmail.

This is what I see in em client log

21:50:23.509|012| A5 LIST "" "%"
21:50:23.509|017| * LIST (\Noinferiors) "/" "INBOX"
21:50:23.511|017| * LIST (\Sent \Noinferiors) "/" "Sent"
21:50:23.511|014| A6 SELECT "INBOX"
21:50:23.521|017| * LIST (\Trash \Noinferiors) "/" "Trash"
21:50:23.547|017| * LIST (\Junk \Noinferiors) "/" "Spam"
21:50:23.560|017| * LIST (\Archive \Noinferiors) "/" "Archive"
21:50:23.570|017| * LIST (\All \Noinferiors) "/" "All Mail"
21:50:23.590|017| * LIST (\Noselect) "/" "Labels"
21:50:23.591|017| * LIST (\Noselect) "/" "Folders"
21:50:23.591|017| A5 OK LIST completed

[jstedfast]

What happens if you manually disable SPECIAL-USE support after Authenticate()?

client.Capabilities &= ~ImapCapabilities.SpecialUse;

[ekalchev]

I am getting the same exceptions with client.Capabilities &= ~ImapCapabilities.SpecialUse;

[jstedfast]

What happens if you change this line: https://github.com/jstedfast/MailKit/blob/master/MailKit/Net/Imap/ImapEngine.cs#L2191

to this?

PersonalNamespaces.Add (new FolderNamespace (list[0].DirectorySeparator, list[0].EncodedName));

[jstedfast]

Wait, never mind, that won't fix it...

[ekalchev]

I tried some commands from a console

tag LIST "" ""
* LIST (\Noselect) "/" "/"
tag OK LIST completed
tag LIST (SPECIAL-USE) "" "*"
tag BAD Reference name must be a string
tag LIST "" "*"
* LIST (\Noinferiors) "/" "INBOX"
* LIST (\Sent \Noinferiors) "/" "Sent"
* LIST (\Trash \Noinferiors) "/" "Trash"
* LIST (\Junk \Noinferiors) "/" "Spam"
* LIST (\Archive \Noinferiors) "/" "Archive"
* LIST (\All \Noinferiors) "/" "All Mail"
* LIST (\Noselect) "/" "Labels"
* LIST (\Noselect) "/" "Folders"
tag OK LIST completed
tag LIST "" "%"
* LIST (\Noinferiors) "/" "INBOX"
* LIST (\Sent \Noinferiors) "/" "Sent"
* LIST (\Trash \Noinferiors) "/" "Trash"
* LIST (\Junk \Noinferiors) "/" "Spam"
* LIST (\Archive \Noinferiors) "/" "Archive"
* LIST (\All \Noinferiors) "/" "All Mail"
* LIST (\Noselect) "/" "Labels"
* LIST (\Noselect) "/" "Folders"
tag OK LIST completed

[jstedfast]

Try changing this line: https://github.com/jstedfast/MailKit/blob/master/MailKit/Net/Imap/ImapEngine.cs#L2255

to this:

ic = new ImapCommand (this, cancellationToken, null, "LIST (SPECIAL-USE) \"\" \"/*\"\r\n");

[jstedfast]

Oh awesome, you can try commands manually. That should be super helpful.

Can you just try sending LIST (SPECIAL-USE) "" "/*"?

Trying to figure out how to make ProtonMail accept that LIST command.

[jstedfast]

Another option might be: LIST (SPECIAL-USE) "/" "*"

[ekalchev]

Same

tag LIST (SPECIAL-USE) "/" "*"
tag BAD Reference name must be a string
tag LIST (SPECIAL-USE) "" "/*"
tag BAD Reference name must be a string

[jstedfast]

Ok, pretty sure that's a bug in ProtonMail's SPECIAL-USE implementation.

The only way I can think of to work around this, then, is to ignore BAD responses to this command and fall back to LIST "" "*" or LIST "" "%"? I'm leaning toward %...

[ekalchev]

My observation to different email client logs shows that all of them use LIST "" "%" for listing folders. This was something I couldn't achieve with mailkit

[jstedfast]

The SPECIAL-USE query is needed to initialize the special folders so that doing client.GetFolder (SpecialFolder.Sent); works.