You can delete tags (Menu >> Tags). Select a tag and edit it, delete it, etc. Double click a tag, change its color or use it for (assign it to) one or more panels (Mails, Events, Tasks, Contacts, Notes). Or click on any of these panels to see which tags were assigned to them.
This been said, a tag is greyed out and you can’t delete it if (among others I believe):
-
It is used by another activity.
-
Or it was assigned by your mail provider or by an outside mail application (for example by Gmail). In Gmail for example, you can manage labels under Settings, categories, Manage labels).
Depending on your eM Client version and your email provider, you can disable/override “external” tags: Menu >> Accounts >> [Select your account] > IMAP >> Tags >> tick the option “Show only locally defined tags”. -
Or you have a rule set up that sets this tag.
-
Or this tag comes from a holiday calendar, for example, that is read-only. You won’t be able to delete a single event an need to remove the whole holiday calendar (if you do not wish to see its events).
Finally, is there any information in Menu >> Operations window regarding the delete attempt?
Hope it helps.