PowerMTA Support Forum

Please login or register.

Login with username, password and session length
Advanced search  

News:

PowerMTA 6.0r4 is out!!!!  Please contact support@port25.com for a license and download access.

Author Topic: Shared DKIMs ( public keys ) can affect deliverability?  (Read 74101 times)

fernandomm

  • Jr. Member
  • **
  • Karma: +2/-14
  • Posts: 20
Shared DKIMs ( public keys ) can affect deliverability?
« on: April 03, 2013, 08:03:25 PM »
Hi,

Does anyone know if sharing the same public key used for DKIM between several domains can affect deliverability?

I started to have some deliverability problems and wanted to know if anyone experienced something similar to it.
Logged

Andrew Edelstein

  • Jr. Member
  • **
  • Karma: +13/-15
  • Posts: 93
Re: Shared DKIMs ( public keys ) can affect deliverability?
« Reply #1 on: April 04, 2013, 11:03:15 AM »
I can't think of any reason why having the same signing key for multiple domains would affect deliverability. If they're all using the same sending IP address, they will share the IP reputation however.
Logged

Teneo

  • Full Member
  • ***
  • Karma: +14/-6
  • Posts: 267
    • Teneo ESP Services
Re: Shared DKIMs ( public keys ) can affect deliverability?
« Reply #2 on: April 09, 2013, 05:07:14 AM »
Well, yes it can ... if you have 1 bad message stream signed with the same DKIM key as the good message stream it will affect it.
More specifically we have seen real life examples of this issue with GMAIL.

If you have the same message content and good practices over multiple sending domains then using the same DKIM should not hurt you.
Logged

AlwindB

  • Jr. Member
  • **
  • Karma: +5/-11
  • Posts: 21
    • Measuremail B.V.
Re: Shared DKIMs ( public keys ) can affect deliverability?
« Reply #3 on: April 09, 2013, 08:10:00 AM »
why use the same key for multiple streams as you can define multiple keys (selectors) per domain? or are you using one identity for signing multiple domains.

In general I would opt for at least an implementation of one DKIM selector per sending domain, this has multiple other advantages.
Logged

FMG123

  • Jr. Member
  • **
  • Karma: +0/-9
  • Posts: 31
Re: Shared DKIMs ( public keys ) can affect deliverability?
« Reply #4 on: April 12, 2013, 11:28:38 AM »
Hi!, so ideally if you use lets say 1 /24 with one domain every 10 or 20 Ips, the ideal configuration in your opinion guys would be to have one DKIM signature per each of those domains?. I.E. for yahoo would that help with preventing TS0...s . Thanks!
Logged

AlwindB

  • Jr. Member
  • **
  • Karma: +5/-11
  • Posts: 21
    • Measuremail B.V.
Re: Shared DKIMs ( public keys ) can affect deliverability?
« Reply #5 on: April 12, 2013, 12:38:49 PM »
by using a DKIM key (selector) per "from" domain, you can start to build build domain reputation.

In general domain reputation is becoming more important, especially with IPv6 around the corner. The default practices for sending email (mostly SPF) are becoming much harder to implement.

To work around all the throttling it's best to implement all solutions (backoff, feedbackloop, spf for ipv4, rdns and dkim)
Logged