Timed out waiting for free conn in pool

[0x11c11e]

Version:

• listmonk: (v2.2.0)
• OS: debian

Once the campaign is started I see this error logs non stop without anything else between lines. The email is authenticated and verified.

2022/09/14 08:43:04error sending message in campaign Third Email Blast: subscriber 84a33edd-9435-479e-9da7-c736a41fd104: timed out waiting for free conn in pool 2022/09/14 08:43:04error sending message in campaign Third Email Blast: subscriber 108d0789-7942-4413-95d2-c933e77db40a: timed out waiting for free conn in pool 2022/09/14 08:43:04error sending message in campaign Third Email Blast: subscriber ebce09cb-af32-4b89-b79c-ca8b656cb3e5: timed out waiting for free conn in pool 2022/09/14 08:43:04error sending message in campaign Third Email Blast: subscriber b3120ce9-4ff7-4ba4-9d2f-2c73b5b6cac5: timed out waiting for free conn in pool 2022/09/14 08:43:04error sending message in campaign Third Email Blast: subscriber e27d845d-6de9-48f3-88a6-5672a6829072: timed out waiting for free conn in pool 2022/09/14 08:43:04error sending message in campaign Third Email Blast: subscriber c062936f-9a36-4e4d-acae-5caf67cfb36e: timed out waiting for free conn in pool 2022/09/14 08:43:04error sending message in campaign Third Email Blast: subscriber 1e6315e6-b1cf-4445-8568-852ee6d9b2d5: timed out waiting for free conn in pool 2022/09/14 08:43:04error sending message in campaign Third Email Blast: subscriber 7de27f4c-213d-49f7-b4ca-d88a3e6b2ca9: timed out waiting for free conn in pool 2022/09/14 08:43:04error sending message in campaign Third Email Blast: subscriber 2ea852ed-7048-4210-bef4-4ed9d89706e3: timed out waiting for free conn in pool 2022/09/14 08:43:04error sending message in campaign Third Email Blast: subscriber 3a37d330-cac5-4306-99f9-c691312b9569: timed out waiting for free conn in pool 2022/09/14 08:43:06error sending message in campaign Third Email Blast: subscriber ed97dd69-8de1-4e64-8785-0dca523f2fda: timed out waiting for free conn in pool 2022/09/14 08:43:06error sending message in campaign Third Email Blast: subscriber dd49ce43-cfac-4531-8da4-1bb2e103577c: timed out waiting for free conn in pool 2022/09/14 08:43:06error sending message in campaign Third Email Blast: subscriber 97f5a540-ab9c-4d59-b94d-c72309258c40: timed out waiting for free conn in pool 2022/09/14 08:43:06error sending message in campaign Third Email Blast: subscriber 3498656d-a2c2-4d36-acef-067cdd85b1a1: timed out waiting for free conn in pool 2022/09/14 08:43:06error sending message in campaign Third Email Blast: subscriber 49fec363-bcad-443c-857f-b9860d835139: timed out waiting for free conn in pool 2022/09/14 08:43:06error sending message in campaign Third Email Blast: subscriber 75065361-4d20-40c1-b575-4565c246205e: timed out waiting for free conn in pool 2022/09/14 08:43:06error sending message in campaign Third Email Blast: subscriber dee1207d-98a7-4b4c-afc0-6d6e737c5639: timed out waiting for free conn in pool

[knadh]

timed out waiting for free conn in pool

SMTP server is slow or overloaded and listmonk's attempts to use an SMTP connection to push out an e-mail is timing out. Try increasing the Max. connections settings in SMTP settings and reducing Concurrency and Message rate in performance settings.

[0x11c11e]

Thanks for your response. I have done that but I started to get a new error:

error sending message in campaign Third Email Blast: subscriber ef750008-4f74-4fd9-9472-ddbf38418c4d: 421 4.7.0 Try again later, closing connection. (MAIL) bq10-20020a05620a468a00b006ce51b541dfsm2109095qkb.36 - gsmtp 2022/09/14 16:01:12error sending message in campaign Third Email Blast: subscriber ec773bd8-b968-45a1-a98b-b95249418630: EOF

[knadh]

421 4.7.0 Try again later.

Looks like you're getting rate limited by Gmail.

https://stackoverflow.com/questions/45756808/bulk-emails-failed-with-421-4-7-0-try-again-later