Errors in snap upgrade to hub 3

Hi, noticed the following errors in the server logs, are they ok or should i do something to fix them?
Error activity Swift_TransportException: Connection could not be established with host 127.0.0.1 :stream_socket_client(): Unable to connect to 127.0.0.1:25 (Connection refused)

[activity] Error: Swift_TransportException: Connection could not be established with host 127.0.0.1 :stream_socket_client(): Unable to connect to 127.0.0.1:25 (Connection refused) at <>

  1. <>
    Swift_Transport_StreamBuffer->{closure}(“*** sensitive parameters replaced ***”)
  2. /snap/nextcloud/33054/htdocs/3rdparty/swiftmailer/swiftmailer/lib/classes/Swift/Transport/StreamBuffer.php line 264
    stream_socket_client()
  3. /snap/nextcloud/33054/htdocs/3rdparty/swiftmailer/swiftmailer/lib/classes/Swift/Transport/StreamBuffer.php line 58
    Swift_Transport_StreamBuffer->establishSocketConnection()
  4. /snap/nextcloud/33054/htdocs/3rdparty/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php line 143
    Swift_Transport_StreamBuffer->initialize()
  5. /snap/nextcloud/33054/htdocs/3rdparty/swiftmailer/swiftmailer/lib/classes/Swift/Mailer.php line 65
    Swift_Transport_AbstractSmtpTransport->start()
  6. /snap/nextcloud/33054/htdocs/lib/private/Mail/Mailer.php line 191
    Swift_Mailer->send()
  7. /snap/nextcloud/33054/htdocs/apps/activity/lib/MailQueueHandler.php line 415
    OC\Mail\Mailer->send()
  8. /snap/nextcloud/33054/htdocs/apps/activity/lib/MailQueueHandler.php line 165
    OCA\Activity\MailQueueHandler->sendEmailToUser()
  9. /snap/nextcloud/33054/htdocs/apps/activity/lib/BackgroundJob/EmailNotification.php line 61
    OCA\Activity\MailQueueHandler->sendEmails()
  10. /snap/nextcloud/33054/htdocs/lib/private/BackgroundJob/Job.php line 54
    OCA\Activity\BackgroundJob\EmailNotification->run()
  11. /snap/nextcloud/33054/htdocs/lib/private/BackgroundJob/TimedJob.php line 60
    OC\BackgroundJob\Job->execute()
  12. /snap/nextcloud/33054/htdocs/cron.php line 152
    OC\BackgroundJob\TimedJob->execute()

at 2023-01-07T05:43:17+00:00