sent folder empty using mailkit

From the MailKit README:

If the IMAP server supports the SPECIAL-USE or the XLIST (GMail) extension, you can get ahold of the pre-defined All, Drafts, Flagged (aka Important), Junk, Sent, Trash, etc folders like this:

if ((client.Capabilities & (ImapCapabilities.SpecialUse | ImapCapabilities.XList)) != 0) { var drafts = client.GetFolder (SpecialFolder.Drafts); } else { // maybe check the user's preferences for the Drafts folder? } 

In cases where the IMAP server does not support the SPECIAL-USE or XLIST extensions, you'll have to come up with your own heuristics for getting the Sent, Drafts, Trash, etc folders. For example, you might use logic similar to this:

static string[] CommonSentFolderNames = { "Sent Items", "Sent Mail", "Sent Messages", /* maybe add some translated names */ }; static IFolder GetSentFolder (ImapClient client, CancellationToken cancellationToken) { var personal = client.GetFolder (client.PersonalNamespaces[0]); foreach (var folder in personal.GetSubfolders (false, cancellationToken)) { foreach (var name in CommonSentFolderNames) { if (folder.Name == name) return folder; } } return null; } 

Using LINQ, you could simplify this down to something more like this:

static string[] CommonSentFolderNames = { "Sent Items", "Sent Mail", "Sent Messages", /* maybe add some translated names */ }; static IFolder GetSentFolder (ImapClient client, CancellationToken cancellationToken) { var personal = client.GetFolder (client.PersonalNamespaces[0]); return personal.GetSubfolders (false, cancellationToken).FirstOrDefault (x => CommonSentFolderNames.Contains (x.Name)); } 

Another option might be to allow the user of your application to configure which folder he or she wants to use as their Sent folder, Drafts folder, Trash folder, etc.

How you handle this is up to you.

It is necessary to open the folder otherwise it will appear empty.

 IMailFolder personal = client.GetFolder(client.PersonalNamespaces[0]); foreach (IMailFolder folder in personal.GetSubfolders(false, cancellationToken)) { folder.Open(FolderAccess.ReadOnly); Console.WriteLine($"folder.Name = {folder.Name}"); Console.WriteLine($"{folder.Name} messages : {folder.Count}"); } 

In addition to @jstedfast's great answer, this turned out to work for me. I'm connecting to Microsoft Exchange IMAP, which does not seem to support SpecialUse or XLIST. It does localize folder names, which can make using a hard-coded folder name heuristic unreliable.

Note that my example looks for the trash folder not the sent folder (on the pro side it is tested in production exactly as written here).

private async Task<IMailFolder?> GetTrashFolderAsync(CancellationToken cancellationToken) { if (_imap.Capabilities.HasFlag(ImapCapabilities.SpecialUse) || _imap.Capabilities.HasFlag(ImapCapabilities.XList)) { return _imap.GetFolder(SpecialFolder.Trash); } _logger?.LogDebug("IMAP server does not support SpecialUse or XList."); var personal = _imap.GetFolder(_imap.PersonalNamespaces[0]); foreach (var folder in await personal.GetSubfoldersAsync(false, cancellationToken)) { if (folder.Attributes.HasFlag(FolderAttributes.Trash)) { _logger?.LogInformation("Found trash folder {fullName} {attr}", folder.FullName, folder.Attributes); return folder; } } _logger?.LogWarning("Found no IMAP trash folder."); return null; }