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Anzine321's avatar
Anzine321
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Sep 23, 2025

smtp port vs 25 and pool member 587

anyone has experience deploy smtp like this :

  1. port on virtual server 25 (plaintext)
  2. pool member 587 (tls)

is that possibel to deploy this ?

3 Replies

  • Hello,

    As per my knowledge - 

     

    • 25 → 587 (TLS) directly = not possible unless the client also speaks STARTTLS.
    • 25 → 25 (both plaintext) =  works.
    • 465/25 (TLS) → 25 (plaintext) =  works with an SSL profile (offload).
    • 25 (plaintext) → 587 (TLS) with protocol translation =  not supported.

    BR
    Aswin

  • I don't see any reason that it won't be possible, but you'll need to configure server ssl profile and probably use iRules as well.