PostSMTP – Always Error in Errorlog

Good day,
we have had a problem with the postman smtp plugin for a long time. The following error is on 2 of our servers and continues like this all day. Here is an excerpt from the error log:

[Mon Dec 06 14:19:50 2021] [notice] TRACE PostmanUtils: Postman memory used: 755.71 KiB
[Mon Dec 06 14:19:50 2021] [notice] TRACE PostmanEmailLogPostType: Created post type: postman_sent_mail
[Mon Dec 06 14:19:50 2021] [notice] DEBUG Postman: local translation file loaded for locale=de_DE
[Mon Dec 06 14:19:50 2021] [notice] TRACE PostmanUtils: calling current_user_can
[Mon Dec 06 14:19:50 2021] [notice] TRACE PostmanUtils: calling current_user_can
[Mon Dec 06 14:19:50 2021] [notice] TRACE PostmanEmailLogPostType: Created post type: postman_sent_mail
[Mon Dec 06 14:19:50 2021] [notice] TRACE PostmanUtils: calling current_user_can
[Mon Dec 06 14:19:54 2021] [notice] DEBUG Postman: Postman SMTP v2.0.23 starting
[Mon Dec 06 14:19:54 2021] [notice] TRACE Postman: SMTP Mailer: postsmtp
[Mon Dec 06 14:19:54 2021] [notice] TRACE PostmanWpMailBinder: Binding to wp_mail()
[Mon Dec 06 14:19:54 2021] [notice] DEBUG PostmanWpMailBinder: Bound to wp_mail()
[Mon Dec 06 14:19:54 2021] [notice] TRACE PostmanUtils: Postman memory used: 757.55 KiB
[Mon Dec 06 14:19:54 2021] [notice] DEBUG Postman: local translation file loaded for locale=de_DE
[Mon Dec 06 14:19:54 2021] [notice] TRACE PostmanUtils: calling current_user_can
[Mon Dec 06 14:19:55 2021] [notice] TRACE PostmanEmailLogPostType: Created post type: postman_sent_mail
[Mon Dec 06 14:19:55 2021] [notice] TRACE PostmanUtils: calling current_user_can
[Mon Dec 06 14:19:57 2021] [notice] DEBUG Postman: Postman SMTP v2.0.23 starting
[Mon Dec 06 14:19:57 2021] [notice] TRACE Postman: SMTP Mailer: postsmtp
[Mon Dec 06 14:19:57 2021] [notice] TRACE PostmanWpMailBinder: Binding to wp_mail()
[Mon Dec 06 14:19:57 2021] [notice] DEBUG PostmanWpMailBinder: Bound to wp_mail()
[Mon Dec 06 14:19:57 2021] [notice] TRACE PostmanUtils: Postman memory used: 757.55 KiB
[Mon Dec 06 14:19:58 2021] [notice] DEBUG Postman: local translation file loaded for locale=de_DE
[Mon Dec 06 14:19:58 2021] [notice] TRACE PostmanUtils: calling current_user_can
[Mon Dec 06 14:19:58 2021] [notice] TRACE PostmanEmailLogPostType: Created post type: postman_sent_mail
[Mon Dec 06 14:19:58 2021] [notice] TRACE PostmanUtils: calling current_user_can`

WordPress is always updated. When you need more information about installation, i can write it here.

Thank you for trying help me.