A Customer Service Mailbox used for daily email to clients is getting blocked by Office 365 Exchange.

Sending automated emails through Office 365 via Java Mail app, the address is getting blocked in Exchange.  I then need to go to Action Center and unblock the account before I can move forward.

Sending roughly 400 email in the early AM and it gets about 300 before is sending starts failing.

What can I do to stop this account/email address from getting blocked on a daily basis?
Dan SheridanSenior System Eng / vITMAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

David Johnson, CD, MVPOwnerCommented:
Use a bulk mailing service i.e. mailchimp
Office 365 has send limits
https://technet.microsoft.com/en-us/library/exchange-online-limits.aspx?f=255&MSPPError=-2147217396

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Vasil Michev (MVP)Commented:
Using O365 in any type of bulk/marketing email scenario will only cause you troubles. You risk your entire IP range(s) getting blocked, not just the account in question. I strongly recommend you start using some of the free services that specialize in bulk emails such as MailChimp or SendGrid, instead of sending those messages via O365.
Dan SheridanSenior System Eng / vITMAuthor Commented:
Moving to a third party emailing app.
David Johnson, CD, MVPOwnerCommented:
author moving to 3rd party emailer
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Office

From novice to tech pro — start learning today.