Multiple Outbound E-Mail creating blacklisting - How to delay each outbound e-mail

[rfvdb]

I'm running Zimbra Community 5.0.16.

Recently had an incident of Outlook jamming about 20 outbound e-mails and then all of a sudden sending them at once (they were all to the same domain). The recieving mail server blacklisted my ip address because of this. The administrators told me it was because the mail server received about 20 e-mails all at the same time from the same IP address.

I want to prevent this from ever occuring again and thought that the best way of doing this would be to delay each outbound e-mail for a second or so. But I can't find anything simple that would do this.

Does anyone know how to do this or have any better ideas? Thanks.

Jonathan

[adeelarifbhatti]

well, I guess it was due to the DNS, the dns may not be working properly and 20 email was gathering in to the queue. When DNS starts working properly emails were deliver to that email server.

Which spam filter was used at remote end, I think your IP address should be blocked by some of the lookups provider services, it can happen if at your end or at service provider end NAT is used. Please check your IP in http://www.spamhaus.org/xbl/index.lasso

Regards
Adeel

[uxbod]

I would tell them that they should greylist instead of blacklist. These type of things can happen.