Test email gives timeout, but error to admin does get delivered!

Hi everyone,

This one is really boggling me: I have a WordPress instance where I try to send email via smtp.domeneshop.no

Every time I try to send a test email, I get as status ‘Connection timed out’. However, right after that I do get the notification delivered to the Admin email.

How is it possible that one fails, but the other works? Is the notification to Admin being sent via a different mechanism?

Mailer: postsmtp
HostName: arkivo.no
cURL Version: 7.68.0
OpenSSL Version: OpenSSL/1.1.1f
OS: Linux ws01 5.15.0-60-generic #66~20.04.1-Ubuntu SMP Wed Jan 25 09:41:30 UTC 2023 x86_64
PHP: Linux 8.1.16 C.UTF-8
PHP Dependencies: iconv=Yes, spl_autoload=Yes, openssl=Yes, sockets=Yes, allow_url_fopen=Yes, mcrypt=No, zlib_encode=Yes
WordPress: 6.1.1 nb_NO UTF-8
WordPress Theme: IKA ?stfold Divi Child Theme
WordPress Plugins: Post SMTP, Cloudflare, Contact Form 7, Divi Accessibility, Site Kit by Google, LiteSpeed Cache, Performance Lab, UpdraftPlus - Backup/Restore, Yoast SEO, Smush
WordPress wp_mail Owner: /home/5/a/arkivo/www/wp-content/plugins/post-smtp/Postman/PostmanWpMailBinder.php
WordPress wp_mail Filter(s): PostsmtpMailer->get_mail_args
WordPress phpmailer_init Action(s): wpcf7_phpmailer_init, PostsmtpMailer->phpmailer_smtp_init
Postman: 2.4.4
Postman Sender Domain (Envelope|Message): arkivost.no | arkivost.no
Postman Prevent Message Sender Override (Email|Name): No | No
Postman Active Transport: SMTP (smtp:tls:login://smtp.domeneshop.no:587)
Postman Active Transport Status (Ready|Connected): Yes | No
Postman Deliveries (Success|Fail): 3 | 3