Why notification is considered as spam, phishing

[M]

Hello there

I'm using Jira 6.0 to send notification by mail and always, it is considered as spam. As i use several external adress ( with JETI plugin), i cannot setup all mail server from customer to accept those mail.

So i wonder what can be the root cause of that because when i write manualy a mail to my customer ( even the first time), this first mail is not considered as spam, so why not with notification from Jira, any idea ?

Thanks in advance.

[Chag]

I believe this is due to the fact that JIRA might send over 100 updates if it is real busy and most mail servers will block or spam due to the fact that a lot are send.