diff --git a/Changelog.md b/Changelog.md
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,5 +1,9 @@
 # Changelog mailpool
 
+# Release 2.3.1 2024.08.14
++ set poolStripeMax to numCapabilities
+  this causes issues if set to a low number. (5)
+
 # Release 2.3.0 2024.08.12 
 + set default to starttls
   + apparantly mailgun requires it by default now
diff --git a/mail-pool.cabal b/mail-pool.cabal
--- a/mail-pool.cabal
+++ b/mail-pool.cabal
@@ -1,7 +1,7 @@
 cabal-version:      3.0
 
 name:           mail-pool
-version:        2.3.0
+version:        2.3.1
 synopsis:       Preconfigured email connection pool on top of smtp.
 description:    Email helper functions with some sane defaults such as a resource pool and cli support
 category:       Email
diff --git a/src/Network/Mail/Pool.hs b/src/Network/Mail/Pool.hs
--- a/src/Network/Mail/Pool.hs
+++ b/src/Network/Mail/Pool.hs
@@ -45,6 +45,7 @@
 import           Network.Socket
 import           Options.Applicative
 import           Type.Reflection             (Typeable)
+import GHC.Conc(numCapabilities)
 
 -- | Failed to authetnicate with some upstream service (smtp for example)
 newtype ServiceAuthFailure a = ServiceAuthFailure a
@@ -103,7 +104,7 @@
   { _poolCred = cred
   , _poolConnf = openTls
   , _poolUnused = 60
-  , _poolStripeMax = 5
+  , _poolStripeMax = numCapabilities
   }
 
 openPlain :: SmtpCred -> IO SMTPConnection