Port25 Support Forum

Please login or register.

Login with username, password and session length
Advanced search  

News:

BREAKING NEWS: PowerMTA 5.0 beta is out!!!!  Please contact support@port25.com for a license and download access.

Author Topic: PMTA - Dns lookups failure  (Read 2234 times)

hlesta

  • Jr. Member
  • **
  • Karma: +0/-0
  • Posts: 30
PMTA - Dns lookups failure
« on: January 24, 2018, 02:56:30 PM »

Hello there,

I'm using DNS-CACHE service with PMTA and I have the following configuration in pmta file.

Code: [Select]


<dns>   
precached-domains-file /etc/pmta/precached-domains
precached-max-domains 500     
precached-refresh-interval 5m
</dns>


Could you please tell me why we can't reach a lot of corporate emails? Someone have some experience with this DNS service? Some configuration or favorite DNS provider?

Thank you!
Logged

Port25-Admin1

  • Administrator
  • Hero Member
  • *****
  • Karma: +42/-6
  • Posts: 2344
Re: PMTA - Dns lookups failure
« Reply #1 on: January 24, 2018, 05:11:23 PM »

What is the DNS TTL for the domains in question?  The feature still uses the TTL to determine when to look up the domain again.  A really short TTL may cause issues as we are constantly having to look it up.
Logged
Port25-Admin1
------------------
Try the following commands:
Quote
pmta show topdomains --errors
pmta show topqueues --errors
pmta --help

When PowerMTA won't start use:
Quote
pmtad --debug
When all else fails-->support@port25.com

hlesta

  • Jr. Member
  • **
  • Karma: +0/-0
  • Posts: 30
Re: PMTA - Dns lookups failure
« Reply #2 on: January 25, 2018, 12:17:20 PM »

What is the DNS TTL for the domains in question?  The feature still uses the TTL to determine when to look up the domain again.  A really short TTL may cause issues as we are constantly having to look it up.

Hello Admin, thanks for your reply.

Do you reffer TTL of domain to send?

When I do a dig -t mx to domain.com, the DNS resolution given is
Code: [Select]
;; connection timed out; no servers could be reached
But if I change to dig @8.8.8.8 -t mx domain.com the DNS resolutions is ok.

So, I change the resolv.conf adding 8.8.8.8 as secundary DNS.

Do you recommend this? Do I to restart pmta? Do you have some additional advice ?

Thank you!
Logged

Port25-Admin1

  • Administrator
  • Hero Member
  • *****
  • Karma: +42/-6
  • Posts: 2344
Re: PMTA - Dns lookups failure
« Reply #3 on: January 26, 2018, 01:18:49 PM »

Sure, just add the following globally:

name-server 8.8.8.8
name-server 8.8.4.4

Once added, reload PowerMTA with "pmta reload"
Logged
Port25-Admin1
------------------
Try the following commands:
Quote
pmta show topdomains --errors
pmta show topqueues --errors
pmta --help

When PowerMTA won't start use:
Quote
pmtad --debug
When all else fails-->support@port25.com

hlesta

  • Jr. Member
  • **
  • Karma: +0/-0
  • Posts: 30
Re: PMTA - Dns lookups failure
« Reply #4 on: January 26, 2018, 02:25:12 PM »

Sure, just add the following globally:

name-server 8.8.8.8
name-server 8.8.4.4

Once added, reload PowerMTA with "pmta reload"

Hello Admin, thank you!!!

We have applied and now we can reach the domain!! thank you!
Logged

CaLViN

  • Hero Member
  • *****
  • Karma: +41/-0
  • Posts: 1233
  • Hasan Kurtoglu
    • PowerMTA Administration Service
Re: PMTA - Dns lookups failure
« Reply #5 on: January 27, 2018, 11:02:16 AM »

Dont use your default dns of your datacenter.
:)
Logged

Professional PowerMTA Administrator - Deliverability Expert

Contact me for Consultancy needs!