diff --git a/GnuPG/__init__.py b/GnuPG/__init__.py
index 540622e..6404720 100644
--- a/GnuPG/__init__.py
+++ b/GnuPG/__init__.py
@@ -101,7 +101,7 @@ def confirm_key( content, email ):
 
 # adds a key and ensures it has the given email address
 def add_key( keyhome, content ):
-	p = subprocess.Popen( build_command(keyhome, '--import', '--batch'), stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE )
+	p = subprocess.Popen( ['/usr/bin/gpg', '--homedir', keyhome, '--import', '--batch'], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE )
 	p.communicate(input=content)
 	p.wait()
 
@@ -130,7 +130,7 @@ class GPGEncryptor:
 		self._message += message
 
 	def encrypt(self):
-		p = subprocess.Popen( self._command(), stdin=subprocess.PIPE, stdout=subprocess.PIPE,stderr=subprocess.PIPE )
+		p = subprocess.Popen( self._command(), stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE )
 		encdata = p.communicate(input=self._message)[0]
 		return (encdata, p.returncode)
 
@@ -158,7 +158,7 @@ class GPGDecryptor:
 		self._message += message
 
 	def decrypt(self):
-		p = subprocess.Popen( self._command(), stdin=subprocess.PIPE, stdout=subprocess.PIPE,stderr=subprocess.PIPE )
+		p = subprocess.Popen( self._command(), stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE )
 		decdata = p.communicate(input=self._message)[0]
 		return (decdata, p.returncode)
 
diff --git a/gpg-mailgate-web/cron.py b/gpg-mailgate-web/cron.py
index 3f305ba..98cd8d1 100644
--- a/gpg-mailgate-web/cron.py
+++ b/gpg-mailgate-web/cron.py
@@ -19,7 +19,7 @@
 #	along with gpg-mailgate source code. If not, see <http://www.gnu.org/licenses/>.
 #
 
-from ConfigParser import RawConfigParser
+from configparser import RawConfigParser
 import GnuPG
 import MySQLdb
 import smtplib
@@ -64,7 +64,7 @@ for sect in _cfg.sections():
 	for (name, value) in _cfg.items(sect):
 		cfg[sect][name] = value
 
-if cfg.has_key('database') and cfg['database'].has_key('enabled') and cfg['database']['enabled'] == 'yes' and cfg['database'].has_key('name') and cfg['database'].has_key('host') and cfg['database'].has_key('username') and cfg['database'].has_key('password'):
+if 'database' in cfg and 'enabled' in cfg['database'] and cfg['database']['enabled'] == 'yes' and 'name' in cfg['database'] and 'host' in cfg['database'] and 'username' in cfg['database'] and 'password' in cfg['database']:
 	connection = MySQLdb.connect(host = cfg['database']['host'], user = cfg['database']['username'], passwd = cfg['database']['password'], db = cfg['database']['name'], port = 3306)
 	cursor = connection.cursor()
 
@@ -83,17 +83,17 @@ if cfg.has_key('database') and cfg['database'].has_key('enabled') and cfg['datab
 				GnuPG.add_key(cfg['gpg']['keyhome'], row[0]) # import the key to gpg
 				cursor.execute("UPDATE gpgmw_keys SET status = 1 WHERE id = %s", (row[1],)) # mark key as accepted
 				appendLog('Imported key from <' + row[2] + '>')
-				if cfg['cron'].has_key('send_email') and cfg['cron']['send_email'] == 'yes':
+				if 'send_email' in cfg['cron'] and cfg['cron']['send_email'] == 'yes':
 					send_msg( "PGP key registration successful", "registrationSuccess.md", row[2] )
 			else:
 				cursor.execute("DELETE FROM gpgmw_keys WHERE id = %s", (row[1],)) # delete key
 				appendLog('Import confirmation failed for <' + row[2] + '>')
-				if cfg['cron'].has_key('send_email') and cfg['cron']['send_email'] == 'yes':
+				if 'send_email' in cfg['cron'] and cfg['cron']['send_email'] == 'yes':
 					send_msg( "PGP key registration failed", "registrationError.md", row[2] )
 		else:
 			# delete key so we don't continue processing it
 			cursor.execute("DELETE FROM gpgmw_keys WHERE id = %s", (row[1],))
-			if cfg['cron'].has_key('send_email') and cfg['cron']['send_email'] == 'yes':
+			if 'send_email' in cfg['cron'] and cfg['cron']['send_email'] == 'yes':
 				send_msg( "PGP key deleted", "keyDeleted.md", row[2])
 
 		connection.commit()
@@ -108,4 +108,4 @@ if cfg.has_key('database') and cfg['database'].has_key('enabled') and cfg['datab
 		appendLog('Deleted key for <' + row[0] + '>')
 		connection.commit()
 else:
-	print "Warning: doing nothing since database settings are not configured!"
+	print("Warning: doing nothing since database settings are not configured!")
diff --git a/gpg-mailgate.py b/gpg-mailgate.py
index b39c786..e520aa5 100755
--- a/gpg-mailgate.py
+++ b/gpg-mailgate.py
@@ -19,7 +19,7 @@
 #	along with gpg-mailgate source code. If not, see <http://www.gnu.org/licenses/>.
 #
 
-from ConfigParser import RawConfigParser
+from configparser import RawConfigParser
 from email.mime.base import MIMEBase
 from email.mime.multipart import MIMEMultipart
 import copy
@@ -94,7 +94,7 @@ def gpg_decrypt( raw_message, recipients ):
 		keys[fingerprint] = sanitize_case_sense(keys[fingerprint])
 
 	for to in recipients:
-		if to in keys.values() and not get_bool_from_cfg('default', 'dec_keymap_only', 'yes'):
+		if to in list(keys.values()) and not get_bool_from_cfg('default', 'dec_keymap_only', 'yes'):
 			gpg_to.append(to)
 		# Is this recipient defined in regex for default decryption?
 		elif not (dec_regex is None) and not (re.match(dec_regex, to) is None):
@@ -106,7 +106,7 @@ def gpg_decrypt( raw_message, recipients ):
 			if not cfg['dec_keymap'][to] in keys:
 				log("Key '%s' in decryption keymap not found in keyring for email address '%s'. Won't decrypt." % (cfg['dec_keymap'][to], to))
 				# Avoid unwanted encryption if set
-				if to in keys.values() and get_bool_from_cfg('default', 'failsave_dec', 'yes'):
+				if to in list(keys.values()) and get_bool_from_cfg('default', 'failsave_dec', 'yes'):
 					noenc_to.append(to)
 				else:
 					ungpg_to.append(to)
@@ -116,7 +116,7 @@ def gpg_decrypt( raw_message, recipients ):
 			if verbose:
 				log("Recipient (%s) not in PGP domain list for decrypting." % to)
 			# Avoid unwanted encryption if set
-			if to in keys.values() and get_bool_from_cfg('default', 'failsave_dec', 'yes'):
+			if to in list(keys.values()) and get_bool_from_cfg('default', 'failsave_dec', 'yes'):
 				noenc_to.append(to)
 			else:
 				ungpg_to.append(to)
@@ -206,7 +206,7 @@ def decrypt_inline_with_attachments( payloads, success, message = None ):
 		message = email.mime.multipart.MIMEMultipart(payloads.get_content_subtype())
 
 	for payload in payloads.get_payload():
-		if( type( payload.get_payload() ) == list ):
+		if( isinstance(payload.get_payload(), list) ):
 			# Take care of cascaded MIME messages
 			submessage, subsuccess = decrypt_inline_with_attachments( payload, success )
 			message.attach(submessage)
@@ -317,7 +317,7 @@ def gpg_encrypt( raw_message, recipients ):
 				log("Key '%s' in encrypt keymap not found in keyring for email address '%s'." % (cfg['enc_keymap'][to], to))
 
 		# Check if key in keychain is present
-		if to in keys.values() and not get_bool_from_cfg('default', 'enc_keymap_only', 'yes'):
+		if to in list(keys.values()) and not get_bool_from_cfg('default', 'enc_keymap_only', 'yes'):
 			gpg_to.append( (to, to) )
 			continue
 
@@ -341,7 +341,7 @@ def gpg_encrypt( raw_message, recipients ):
 		ungpg_to.append(to)
 
 	if gpg_to != list():
-		log("Encrypting email to: %s" % ' '.join( map(lambda x: x[0], gpg_to) ))
+		log("Encrypting email to: %s" % ' '.join( [x[0] for x in gpg_to] ))
 
 		# Getting PGP style for recipient
 		gpg_to_smtp_mime = list()
@@ -378,8 +378,8 @@ def gpg_encrypt( raw_message, recipients ):
 			if get_bool_from_cfg('default', 'add_header', 'yes'):
 				raw_message_mime['X-GPG-Mailgate'] = 'Encrypted by GPG Mailgate'
 
-			if raw_message_mime.has_key('Content-Transfer-Encoding'):
-                                raw_message_mime.replace_header('Content-Transfer-Encoding','8BIT')
+			if 'Content-Transfer-Encoding' in raw_message_mime:
+                                raw_message_mime.replace_header('Content-Transfer-Encoding', '8BIT')
                         else:
                                 raw_message_mime['Content-Transfer-Encoding'] = '8BIT'
 
@@ -395,8 +395,8 @@ def gpg_encrypt( raw_message, recipients ):
 			if get_bool_from_cfg('default', 'add_header', 'yes'):
 				raw_message_inline['X-GPG-Mailgate'] = 'Encrypted by GPG Mailgate'
 
-			if raw_message_inline.has_key('Content-Transfer-Encoding'):
-                                raw_message_inline.replace_header('Content-Transfer-Encoding','8BIT')
+			if 'Content-Transfer-Encoding' in raw_message_inline:
+                                raw_message_inline.replace_header('Content-Transfer-Encoding', '8BIT')
                         else:
                                 raw_message_inline['Content-Transfer-Encoding'] = '8BIT'
 
@@ -411,11 +411,11 @@ def encrypt_all_payloads_inline( message, gpg_to_cmdline ):
 
 	# This breaks cascaded MIME messages. Blame PGP/INLINE.
 	encrypted_payloads = list()
-	if type( message.get_payload() ) == str:
+	if isinstance(message.get_payload(), str):
 		return encrypt_payload( message, gpg_to_cmdline ).get_payload()
 
 	for payload in message.get_payload():
-		if( type( payload.get_payload() ) == list ):
+		if( isinstance(payload.get_payload(), list) ):
 			encrypted_payloads.extend( encrypt_all_payloads_inline( payload, gpg_to_cmdline ) )
 		else:
 			encrypted_payloads.append( encrypt_payload( payload, gpg_to_cmdline ) )
@@ -437,13 +437,13 @@ def encrypt_all_payloads_mime( message, gpg_to_cmdline ):
 	submsg2.set_param('inline', "",                'Content-Disposition' )
 	submsg2.set_param('filename', "encrypted.asc", 'Content-Disposition' )
 
-	if type ( message.get_payload() ) == str:
+	if isinstance(message.get_payload(), str):
 		# WTF!  It seems to swallow the first line.  Not sure why.  Perhaps
 		# it's skipping an imaginary blank line someplace. (ie skipping a header)
 		# Workaround it here by prepending a blank line.
 		# This happens only on text only messages.
 		additionalSubHeader=""
-		if message.has_key('Content-Type') and not message['Content-Type'].startswith('multipart'):
+		if 'Content-Type' in message and not message['Content-Type'].startswith('multipart'):
 			additionalSubHeader="Content-Type: "+message['Content-Type']+"\n"
 		submsg2.set_payload(additionalSubHeader+"\n" +message.get_payload(decode=True))
 		check_nested = True
@@ -460,7 +460,7 @@ def encrypt_all_payloads_mime( message, gpg_to_cmdline ):
 	boundary = junk_msg.get_boundary()
 
     # This also modifies the boundary in the body of the message, ie it gets parsed.
-	if message.has_key('Content-Type'):
+	if 'Content-Type' in message:
 		message.replace_header('Content-Type', "multipart/encrypted; protocol=\"application/pgp-encrypted\";\nboundary=\"%s\"\n" % boundary)
 	else:
 		message['Content-Type'] = "multipart/encrypted; protocol=\"application/pgp-encrypted\";\nboundary=\"%s\"\n" % boundary
@@ -608,7 +608,7 @@ def generate_message_from_payloads( payloads, message = None ):
 		message = email.mime.multipart.MIMEMultipart(payloads.get_content_subtype())
 
 	for payload in payloads.get_payload():
-		if( type( payload.get_payload() ) == list ):
+		if( isinstance(payload.get_payload(), list) ):
 			message.attach(generate_message_from_payloads(payload))
 		else:
 			message.attach(payload)
@@ -624,7 +624,7 @@ def get_first_payload( payloads ):
 
 def send_msg( message, recipients ):
 
-	recipients = filter(None, recipients)
+	recipients = [_f for _f in recipients if _f]
 	if recipients:
 		if not (get_bool_from_cfg('relay', 'host') and get_bool_from_cfg('relay', 'port')):
 			log("Missing settings for relay. Sending email aborted.")
@@ -632,7 +632,7 @@ def send_msg( message, recipients ):
 		log("Sending email to: <%s>" % '> <'.join( recipients ))
 		relay = (cfg['relay']['host'], int(cfg['relay']['port']))
 		smtp = smtplib.SMTP(relay[0], relay[1])
-                if cfg.has_key('relay') and cfg['relay'].has_key('starttls') and cfg['relay']['starttls'] == 'yes':
+                if 'relay' in cfg and 'starttls' in cfg['relay'] and cfg['relay']['starttls'] == 'yes':
                     smtp.starttls()
 		smtp.sendmail( from_addr, recipients, message )
 	else:
diff --git a/register-handler.py b/register-handler.py
index 5b1cf9a..f4c1e57 100644
--- a/register-handler.py
+++ b/register-handler.py
@@ -1,6 +1,6 @@
 #!/usr/bin/python
 
-from ConfigParser import RawConfigParser
+from configparser import RawConfigParser
 import email, os, smtplib, sys, traceback, markdown, syslog, requests
 from M2Crypto import BIO, Rand, SMIME, X509
 
@@ -17,7 +17,7 @@ for sect in _cfg.sections():
 		cfg[sect][name] = value
 
 def log(msg):
-	if cfg.has_key('logging') and cfg['logging'].has_key('file'):
+	if 'logging' in cfg and 'file' in cfg['logging']:
 		if cfg['logging']['file'] == "syslog":
 			syslog.syslog(syslog.LOG_INFO | syslog.LOG_MAIL, msg)
 		else:
@@ -78,9 +78,9 @@ if __name__ == "__main__":
 			sys.exit(0)
 		
 		if sign_type == 'smime':
-			raw_sig = sign_part.get_payload().replace("\n","")
+			raw_sig = sign_part.get_payload().replace("\n", "")
 			# re-wrap signature so that it fits base64 standards
-			cooked_sig = '\n'.join(raw_sig[pos:pos+76] for pos in xrange(0, len(raw_sig), 76))
+			cooked_sig = '\n'.join(raw_sig[pos:pos+76] for pos in range(0, len(raw_sig), 76))
 			
 			# now, wrap the signature in a PKCS7 block
 			sig = """
@@ -106,7 +106,7 @@ if __name__ == "__main__":
 			# format in user-specific data
 			# sending success mail only for S/MIME as GPGMW handles this on its own
 			success_msg = file(cfg['mailregister']['mail_templates']+"/registrationSuccess.md").read()
-			success_msg = success_msg.replace("[:FROMADDRESS:]",from_addr)
+			success_msg = success_msg.replace("[:FROMADDRESS:]", from_addr)
 			
 			msg = MIMEMultipart("alternative")
 			msg["From"] = cfg['mailregister']['register_email']
@@ -128,7 +128,7 @@ if __name__ == "__main__":
 			if r.status_code != 200:
 				log("Could not hand registration over to GPGMW. Error: %s" % r.status_code)
 				error_msg = file(cfg['mailregister']['mail_templates']+"/gpgmwFailed.md").read()
-				error_msg = error_msg.replace("[:FROMADDRESS:]",from_addr)
+				error_msg = error_msg.replace("[:FROMADDRESS:]", from_addr)
 			
 				msg = MIMEMultipart("alternative")
 				msg["From"] = cfg['mailregister']['register_email']
diff --git a/test/e2e_test.py b/test/e2e_test.py
index d53d6d9..0f7705f 100644
--- a/test/e2e_test.py
+++ b/test/e2e_test.py
@@ -24,7 +24,7 @@ import sys
 
 import difflib
 
-import ConfigParser
+import configparser
 import logging
 
 from time import sleep
@@ -35,7 +35,7 @@ CONFIG_FILE = "test/gpg-mailgate.conf"
 PYTHON_BIN = "python2.7"
 
 def build_config(config):
-    cp = ConfigParser.ConfigParser()
+    cp = configparser.ConfigParser()
 
     cp.add_section("logging")
     cp.set("logging", "file", config["log_file"])
@@ -83,7 +83,7 @@ def report_result(message_file, expected, test_output):
     else:
         status = "Failure"
 
-    print message_file.ljust(30), status
+    print(message_file.ljust(30), status)
 
 def execute_e2e_test(case_name, config, config_path):
     """Read test case configuration from config and run that test case.
@@ -116,7 +116,7 @@ def execute_e2e_test(case_name, config, config_path):
     report_result(config.get(case_name, "in"), config.get(case_name, "out"), testout)
 
 def load_test_config():
-    cp = ConfigParser.ConfigParser()
+    cp = configparser.ConfigParser()
     cp.read("test/e2e.ini")
 
     return cp
@@ -146,4 +146,4 @@ for case_no in range(1, config.getint("tests", "cases")+1):
 
     execute_e2e_test(case_name, config, config_path)
 
-print "See diagnostic output for details. Tests: '%s', Lacre: '%s'" % (config.get("tests", "e2e_log"), config.get("tests", "lacre_log"))
+print("See diagnostic output for details. Tests: '%s', Lacre: '%s'" % (config.get("tests", "e2e_log"), config.get("tests", "lacre_log")))
diff --git a/test/relay.py b/test/relay.py
index 01b93d4..bc6969c 100644
--- a/test/relay.py
+++ b/test/relay.py
@@ -40,8 +40,8 @@ def serve(port):
 	try:
 		s.bind(('', port))
 		s.listen(1)
-	except socket.error, e:
-		print "Cannot connect", e
+	except socket.error as e:
+		print("Cannot connect", e)
 		sys.exit(EXIT_UNAVAILABLE)
 
 	(conn, addr) = s.accept()
@@ -69,7 +69,7 @@ def serve(port):
 	return message[:-len(EOM)]
 
 def error(msg):
-	print "ERROR: %s" % (msg)
+	print("ERROR: %s" % (msg))
 	sys.exit(1)
 
 
@@ -79,4 +79,4 @@ if len(sys.argv) < 2:
 port = int(sys.argv[1])
 body = serve(port)
 
-print body
+print(body)