Error on Issue module

Hi,
i am getting this kind of error on “issue” while connected with my email account. while receiving an e-mail, the replay with issue tracking number is not sending automatically…

Error 1

Traceback (most recent call last):
File “/home/frappe/benches/bench-2017-11-28/apps/frappe/frappe/email/receive.py”, line 72, in connect_pop
self.pop = Timed_POP3_SSL(self.settings.host, timeout=frappe.conf.get(“pop_timeout”))
File “/home/frappe/benches/bench-2017-11-28/apps/frappe/frappe/email/receive.py”, line 550, in init
self._super.init(self, *args, **kwargs)
File “/usr/lib64/python2.7/poplib.py”, line 346, in init
for res in socket.getaddrinfo(self.host, self.port, 0, socket.SOCK_STREAM):
gaierror: [Errno -2] Name or service not known

Error 2
[Errno -2] Name or service not known
Traceback (most recent call last):
File “/home/frappe/benches/bench-2017-11-28/apps/frappe/frappe/email/queue.py”, line 412, in send_one
smtpserver.sess.sendmail(email.sender, recipient.recipient, encode(message))
File “/home/frappe/benches/bench-2017-11-28/apps/frappe/frappe/email/smtp.py”, line 208, in sess
raise_(frappe.ValidationError, e, traceback)
File “/home/frappe/benches/bench-2017-11-28/apps/frappe/frappe/email/smtp.py”, line 181, in sess
cint(self.port) or None)
File “/usr/lib64/python2.7/smtplib.py”, line 255, in init
(code, msg) = self.connect(host, port)
File “/usr/lib64/python2.7/smtplib.py”, line 315, in connect
self.sock = self._get_socket(host, port, self.timeout)
File “/usr/lib64/python2.7/smtplib.py”, line 290, in _get_socket
return socket.create_connection((host, port), timeout)
File “/usr/lib64/python2.7/socket.py”, line 553, in create_connection
for res in getaddrinfo(host, port, 0, SOCK_STREAM):
ValidationError: [Errno -2] Name or service not known

Error 3
[Errno 110] Connection timed out
Traceback (most recent call last):
File “/home/frappe/benches/bench-2017-11-28/apps/frappe/frappe/email/queue.py”, line 412, in send_one
smtpserver.sess.sendmail(email.sender, recipient.recipient, encode(message))
File “/home/frappe/benches/bench-2017-11-28/apps/frappe/frappe/email/smtp.py”, line 208, in sess
raise_(frappe.ValidationError, e, traceback)
File “/home/frappe/benches/bench-2017-11-28/apps/frappe/frappe/email/smtp.py”, line 181, in sess
cint(self.port) or None)
File “/usr/lib64/python2.7/smtplib.py”, line 255, in init
(code, msg) = self.connect(host, port)
File “/usr/lib64/python2.7/smtplib.py”, line 315, in connect
self.sock = self._get_socket(host, port, self.timeout)
File “/usr/lib64/python2.7/smtplib.py”, line 290, in _get_socket
return socket.create_connection((host, port), timeout)
File “/usr/lib64/python2.7/socket.py”, line 571, in create_connection
raise err
ValidationError: [Errno 110] Connection timed out