from evolution-data-server/trunk/camel/providers/imap/camel-imap-folder.c:

mi = (CamelImapMessageInfo *)camel_folder_summary_uid (folder->summary, uid);
if (mi == NULL) {
	camel_exception_setv(ex, CAMEL_EXCEPTION_FOLDER_INVALID_UID,
  	         _("Cannot get message: %s\n %s"), uid, _("No such message"));
  	return NULL;
}

that results in an ugly error message, also because the \n doesn't work in my 2.22:
English version: "Cannot get message: 1926 No such message"
German version, translated to english:
"Could not fetch message: 1926 Message does not exist"

what about "Cannot get message with message ID %s: No such message available." ?