Allow to configure SMTP host and From address

config.py

@@ -8,6 +8,10 @@ config.base_tick = 60
 
 # Email addresses to send to when an alert is triggered
 config.emails.to.append('john@localhost')
+# The From: address
+#config.emails.addr_from = 'Picomon <picomon@domain.tld>
+# The SMTP host, with optional :port suffix
+#config.emails.smtp_host = 'localhost:25'
 
 # Subject template for state change email notifications
 # available substitutions:

lib/__init__.py

+import socket
 from .attrtree import AttrTree
 from .checks import Checks
 
@@ -13,6 +14,11 @@ config.install_attr('base_tick', 60)
 
 # Email addresses to send to when an alert is triggered
 config.install_attr('emails.to', [])
+# The From: address
+config.install_attr('emails.addr_from',
+                    'Picomon <picomon@%s>' % socket.getfqdn())
+# The SMTP host, with optional :port suffix
+config.install_attr('emails.smtp_host', 'localhost:25')
 
 # Subject template for state change email notifications
 # available substitutions:

lib/mails.py

-import socket
 import smtplib
 from email.mime.text import MIMEText
 from collections import defaultdict
@@ -11,8 +10,6 @@ email.charset.add_charset('utf-8', email.charset.QP, email.charset.QP, 'utf-8')
 
 def send_email_for_check(check):
     from . import config
-    addr_from  = "Picomon <picomon@%s>" % socket.getfqdn()
-
     # ensure we do not traceback with unknown substitutions
     subject = config.emails.subject_tpl.format_map(
               defaultdict(lambda: "<no substitution>",
@@ -29,13 +26,13 @@ def send_email_for_check(check):
     # http://bugs.python.org/issue16948
     msg = MIMEText(msg_text.encode('utf-8').decode('latin1'), 'plain', 'utf-8')
     msg['Subject'] = subject
-    msg['From']    = addr_from
+    msg['From']    = config.emails.addr_from
     msg['To']      = ", ".join(config.emails.to)
 
     try:
-        server = smtplib.SMTP('localhost')
+        server = smtplib.SMTP(config.emails.smtp_host)
         # server.set_debuglevel(1)
-        server.sendmail(addr_from, config.emails.to, msg.as_string())
+        server.sendmail(config.emails.addr_from, config.emails.to, msg.as_string())
         server.quit()
     except Exception as e:
         print("Couldn't send email: %s" % str(e), file=stderr)