diff --git a/Mailnag/backends/imap.py b/Mailnag/backends/imap.py
index ddb0a25..deab175 100644
--- a/Mailnag/backends/imap.py
+++ b/Mailnag/backends/imap.py
@@ -82,9 +82,9 @@ class IMAPMailboxBackend(MailboxBackend):
 
 		for folder in folder_list:
 			# select IMAP folder
-			conn.select(f'"{folder}"', readonly = True)
+			conn.select(f'"{folder}"')
 			try:
-				status, data = conn.search(None, 'UNSEEN') # ALL or UNSEEN
+				status, data = conn.uid('SEARCH', None, '(UNSEEN)') # ALL or UNSEEN
 			except:
 				logging.warning('Folder %s does not exist.', folder)
 				continue
@@ -93,7 +93,7 @@ class IMAPMailboxBackend(MailboxBackend):
 				logging.debug('Folder %s in status %s | Data: %s', (folder, status, data))
 				continue # Bugfix LP-735071
 			for num in data[0].split():
-				typ, msg_data = conn.fetch(num, '(BODY.PEEK[HEADER])') # header only (without setting READ flag)
+				typ, msg_data = conn.uid('FETCH', num, '(BODY.PEEK[HEADER])') # header only (without setting READ flag)
 				for response_part in msg_data:
 					if isinstance(response_part, tuple):
 						try:
@@ -101,7 +101,7 @@ class IMAPMailboxBackend(MailboxBackend):
 						except:
 							logging.debug("Couldn't get IMAP message.")
 							continue
-						yield (folder, msg)
+						yield (folder, msg, num.decode("utf-8"))
 
 
 	def request_folders(self):
@@ -225,8 +225,7 @@ class IMAPMailboxBackend(MailboxBackend):
 			folder = self.folders[0]
 		else:
 			folder = "INBOX"
-		
-		conn.select(f'"{folder}"', readonly = True)
+		conn.select(f'"{folder}"')
 	
 	def _ensure_open(self):
 		if not self.is_open():
diff --git a/Mailnag/common/config.py b/Mailnag/common/config.py
index fcbdf2d..f638537 100644
--- a/Mailnag/common/config.py
+++ b/Mailnag/common/config.py
@@ -26,6 +26,7 @@ mailnag_defaults = {
 		'poll_interval'		: '10',
 		'imap_idle_timeout'	: '10',
 		'autostart'			: '1',
+		'mark_imap_read'	: '1',
 		'connectivity_test'	: 'auto',
 		'enabled_plugins'	: 'dbusplugin, soundplugin, libnotifyplugin'
 	}
diff --git a/Mailnag/daemon/dbus.py b/Mailnag/daemon/dbus.py
index c8d01ac..e420adb 100644
--- a/Mailnag/daemon/dbus.py
+++ b/Mailnag/daemon/dbus.py
@@ -110,7 +110,7 @@ class DBusService(dbus.service.Object):
 			d['sender_addr'] = addr				# string (s)
 			d['account_name'] = m.account_name	# string (s)
 			d['id'] = m.id						# string (s)
-
+			d['strID'] = m.strID				# string (s)
 			converted_mails.append(d)
 		
 		return converted_mails
diff --git a/Mailnag/daemon/mailchecker.py b/Mailnag/daemon/mailchecker.py
index 6df9de0..5a2bd0f 100644
--- a/Mailnag/daemon/mailchecker.py
+++ b/Mailnag/daemon/mailchecker.py
@@ -36,6 +36,7 @@ class MailChecker:
 		self._conntest = conntest
 		self._dbus_service = dbus_service
 		self._count_on_last_check = 0
+		self._all_mails = []
 		
 	
 	def check(self, accounts):
@@ -65,7 +66,7 @@ class MailChecker:
 				else: # mail is fetched the first time
 					unseen_mails.append(mail)
 					new_mails.append(mail)
-			
+			self._all_mails = all_mails
 			self._memorizer.sync(all_mails)
 			self._memorizer.save()
 			self._firstcheck = False
diff --git a/Mailnag/daemon/mailnagdaemon.py b/Mailnag/daemon/mailnagdaemon.py
index 07b759a..d452a3b 100644
--- a/Mailnag/daemon/mailnagdaemon.py
+++ b/Mailnag/daemon/mailnagdaemon.py
@@ -126,9 +126,22 @@ class MailnagDaemon(MailnagController):
 	
 	# Part of MailnagController interface
 	def mark_mail_as_read(self, mail_id):
-		# Note: ensure_not_disposed() is not really necessary here
-		# (the memorizer object is available in dispose()), 
-		# but better be consistent with other daemon methods.
+		mails = self._mailchecker._all_mails
+		found = False
+		for mail in mails:
+			if mail_id == mail.id:
+				found = True
+				break
+		if (not found) or (not bool(int(self._cfg.get('core', 'mark_imap_read')))):
+			self._ensure_not_disposed()
+			self._memorizer.set_to_seen(mail_id)
+			self._memorizer.save()
+			return
+		backend = mail.account._get_backend()
+		if type(backend).__name__ == 'IMAPMailboxBackend':
+			mailid = mail.strID
+			conn = backend._conn
+			status, res = conn.uid("STORE", mailid, "+FLAGS", "(\Seen)")
 		self._ensure_not_disposed()
 		self._memorizer.set_to_seen(mail_id)
 		self._memorizer.save()
diff --git a/Mailnag/daemon/mails.py b/Mailnag/daemon/mails.py
index 594c01f..c144547 100644
--- a/Mailnag/daemon/mails.py
+++ b/Mailnag/daemon/mails.py
@@ -35,13 +35,15 @@ from Mailnag.common.config import cfg_folder
 # Mail class
 #
 class Mail:
-	def __init__(self, datetime, subject, sender, id, account):
+	def __init__(self, datetime, subject, sender, id, account, strID):
 		self.datetime = datetime
 		self.subject = subject
 		self.sender = sender
+		self.account = account
 		self.account_name = account.name
 		self.account_id = account.get_id()
 		self.id = id
+		self.strID = strID
 
 
 #
@@ -66,7 +68,7 @@ class MailCollector:
 				logging.error("Failed to open mailbox for account '%s' (%s)." % (acc.name, ex))
 				continue
 
-			for folder, msg in acc.list_messages():
+			for folder, msg, num in acc.list_messages():
 				sender, subject, datetime, msgid = self._get_header(msg)
 				id = self._get_id(msgid, acc, folder, sender, subject, datetime)
 			
@@ -78,7 +80,7 @@ class MailCollector:
 				# Also filter duplicates caused by Gmail labels.
 				if id not in mail_ids:
 					mail_list.append(Mail(datetime, subject, \
-						sender, id, acc))
+						sender, id, acc, num))
 					mail_ids[id] = None
 
 			# leave account with notifications open, so that it can
@@ -193,7 +195,6 @@ class MailSyncer:
 		
 		# collect mails from given accounts
 		rcv_lst = MailCollector(self._cfg, accounts).collect_mail(sort = False)
-	
 		# group received mails by account
 		tmp = {}
 		for acc in accounts: