Not the most helpful game master, but basically he is saying the same; warning that an addon automating ingame functions may get you banned, but not confirming whether or not this addon is one of them. Once again, I urge you to be careful and wait for a final answer from a GM that knows all the regulations about addons.
22:31:35 <GM>[Tarentithia] whispers: Greetings Zerotorescue, I am Game Master Tarentithia. Sorry to interrupt your play. Do you have a moment so we can deal with the issue concerning your Mailbox Addon?
22:31:52 To [Tarentithia]: Certainly
22:32:04 <GM>[Tarentithia] whispers: Great

How are you today?
22:32:20 To [Tarentithia]: I am fine, thanks for asking, how about you?

22:32:28 <GM>[Tarentithia] whispers: I am very well thank you.

22:33:03 <GM>[Tarentithia] whispers: Now then
22:33:06 <GM>[Tarentithia] whispers: About this addon:
22:33:11 <GM>[Tarentithia] whispers: Basicaly:
22:33:33 <GM>[Tarentithia] whispers: Any addon that has any automated action, can be considered a botting mechanism.
22:33:38 To [Tarentithia]: basically what it does every 10 seconds is run a /script CheckInbox and then use a second addon to open the mail
22:33:54 To [Tarentithia]: it's an ingame addon requiring no external tools
22:34:07 To [Tarentithia]: using the provided ingame commands
22:34:13 <GM>[Tarentithia] whispers: Indeed, but it uses alot of /scripting commands.
22:34:55 <GM>[Tarentithia] whispers: Basicaly I cannot tell you the exact stand point on this addon, but I will warn you that any addons that use any automated functions can be considered as botting. And can have serious negative effects on one's account
22:35:41 To [Tarentithia]: Is there a posibility that you can verify this with a person that knows the technical stuff about addons?

22:36:14 <GM>[Tarentithia] whispers: This is not a possibility. We cannot say yes or no to specific addons, only advise players.
22:36:18 To [Tarentithia]: I understand your usual reply is to say that automation is bad and to warn the player so that you are not responsible if the player is banned if in any case the addon is against your rules, however, I would like a final answer
22:36:29 <GM>[Tarentithia] whispers: This is the final answer.
22:37:03 To [Tarentithia]: I was afraid it would be
22:38:21 <GM>[Tarentithia] whispers:
http://www.wow-europe.com/en/policy/exp ... n.html#mum is where you can see the list of policies for this kind of matter.
22:38:39 <GM>[Tarentithia] whispers: We cannot say any more on this matter.
22:39:52 <GM>[Tarentithia] whispers: And I shall bid you farewell now, as other players require my assistance.
22:40:12 To [Tarentithia]: alright, bye.