postfix 450 4.7.25 + false postive

Discuss your pilot or production implementation with other Zimbra admins or our engineers.
pattonb
Posts: 11
Joined: Sat Jul 01, 2017 3:09 am
ZCS/ZD Version: 8.7.6

postfix 450 4.7.25 + false postive

Postby pattonb » Mon Aug 21, 2017 12:58 am

I see mail coming in and getting rejected with the "450 4.7.25 " Client host rejected: cannot find your hostname, [xx.xxx.xx.xxx], yet when
I do a ptr look up on the ip it matches the "helo=fqdn"

Where to check next ?


User avatar
stefaniu.criste
Posts: 38
Joined: Wed Feb 12, 2014 5:40 am
Location: Romania
ZCS/ZD Version: 8.8.8_GA_1728 20180614052922 201806
Contact:

Re: postfix 450 4.7.25 + false postive

Postby stefaniu.criste » Mon Aug 21, 2017 5:59 am

Do you see this behavior for a single domain, or randomly, for multiple domains ?
What DNS servers do you use as resolvers ?
Stefaniu Criste - managing partner
Hangar Hosting - a safe place for your business
proudly delivering Zimbra services in Romania
pattonb
Posts: 11
Joined: Sat Jul 01, 2017 3:09 am
ZCS/ZD Version: 8.7.6

Re: postfix 450 4.7.25 + false postive

Postby pattonb » Mon Aug 21, 2017 2:45 pm

I see this behavior with a number of different domains.
The dns resolvers are the upstream isp providers dns servers.
User avatar
Carlos A. P. Cunha
Posts: 48
Joined: Fri Feb 19, 2016 11:47 am

Re: postfix 450 4.7.25 + false postive

Postby Carlos A. P. Cunha » Thu Aug 24, 2017 3:25 pm

Hello!
This problem is because sender is information HELO=XXXXXX, this XXXX no possible resolved ins dns.
This Check enable in Zimbra(Web -> MTA -> Check hostname)

Regads,

Return to “Administrators”

Who is online

Users browsing this forum: No registered users and 22 guests