Dear SmarterMail team,

I notice problems sendig outgoing mail via a gateway since upgrading to smartermail running on dot.net V8. The setup wasn't changed since years. My mail provider is german strato, a really huge company.

All outgoing mail is send to thier smt.server smtp.strato.de, port 465, SSL.

In the logs I see ...

20:02:34.580 [42485000] Sending remote mail from lars@koellers.net
20:02:34.818 [42485000] Failed to connect to the recipient's mail server. No MX records were found for the 'smtp.strato.de' domain. Failing over to A records.
20:02:34.818 [42485000] MXRecord count: '1' for domain ''
20:02:34.818 [42485000] Attempting MXRecord Host Name: 'smtp.strato.de', preference '1', Ip Count: '1'
20:02:34.818 [42485000] Attempting to send to MXRecord 'smtp.strato.de' ip: '81.169.145.133'
20:02:34.819 [42485000] Sending remote mail to: XXXXX@icloud.com
20:02:34.820 [42485000] Initiating connection to 81.169.145.133
20:02:34.820 [42485000] Connecting to 81.169.145.133:465 (Id: 1)
20:02:34.868 [42485000] Connection to 81.169.145.133:465 from 192.168.5.40:57655 succeeded (Id: 1)
20:03:34.957 [42485000] RSP: 220 smtp.strato.de ESMTP RZmta (P8 -)
20:03:34.959 [42485000] CMD: EHLO mail.koellers.net
20:04:34.982 [42485000] The smtp session has timed out.
20:04:34.983 [42485000] Attempt to ip, '81.169.145.133' success: 'False'
20:04:34.983 [42485000] Failed to send to gateway smtp.strato.de using MX Lookups, error string: Failed to connect to the recipient's mail server.  No MX records were found for the 'smtp.strato.de' domain.
Status: 544 5.4.4 Host not found (not in DNS).Attempted to send the message to the following IPs:
    81.169.145.133
20:04:34.992 [42485000] Removed from RemoteDeliveryQueue (0 queued or processing)
20:08:02.357 [04438007] Added to RemoteDeliveryQueue (1 queued; 0/50 processing)
20:08:02.357 [04438007] [RemoteDeliveryQueue] Begin Processing.
20:08:02.359 [04438007] Sending remote mail from lars@koellers.net
20:08:02.409 [04438007] Failed to connect to the recipient's mail server. No MX records were found for the 'smtp.strato.de' domain. Failing over to A records.
20:08:02.409 [04438007] MXRecord count: '1' for domain ''
20:08:02.409 [04438007] Attempting MXRecord Host Name: 'smtp.strato.de', preference '1', Ip Count: '1'
20:08:02.409 [04438007] Attempting to send to MXRecord 'smtp.strato.de' ip: '81.169.145.133'
20:08:02.409 [04438007] Sending remote mail to: XXXXXXXX@icloud.com
20:08:02.409 [04438007] Initiating connection to 81.169.145.133
20:08:02.409 [04438007] Connecting to 81.169.145.133:465 (Id: 1)
20:08:02.437 [04438007] Connection to 81.169.145.133:465 from 192.168.5.40:57704 succeeded (Id: 1)
20:08:02.479 [04438007] RSP: 220 smtp.strato.de ESMTP RZmta (P12 -)
20:08:02.480 [04438007] CMD: EHLO mail.koellers.net
20:08:02.511 [04438007] RSP: 250-smtp.strato.de greets xx.79.yyyy.94
20:08:02.512 [04438007] RSP: 250-ENHANCEDSTATUSCODES
20:08:02.512 [04438007] RSP: 250-PIPELINING
20:08:02.512 [04438007] RSP: 250-8BITMIME
20:08:02.512 [04438007] RSP: 250-DELIVERBY
20:08:02.512 [04438007] RSP: 250-SIZE 104857600
20:08:02.512 [04438007] RSP: 250-LIMITS RCPTMAX=1000 MAILMAX=1000
20:08:02.512 [04438007] RSP: 250-AUTH PLAIN LOGIN CRAM-MD5 DIGEST-MD5
20:08:02.512 [04438007] RSP: 250-REQUIRETLS
20:08:02.512 [04438007] RSP: 250 HELP
20:08:02.512 [04438007] CMD: AUTH LOGIN
20:08:02.545 [04438007] RSP: 334 VXNlcm5hbWU6
20:08:02.578 [04438007] RSP: 334 UGFzc3dvcmQ6
20:08:02.613 [04438007] RSP: 235 2.7.0 OK Authenticated
20:08:02.614 [04438007] CMD: MAIL FROM:<lars@koellers.net> SIZE=651
20:08:02.645 [04438007] RSP: 250 2.1.0 Sender ok
20:08:02.645 [04438007] CMD: RCPT TO:<lars_koeller@icloud.com>
20:08:02.676 [04438007] RSP: 250 2.1.5 Recipient ok: <lars_koeller@icloud.com>
20:08:02.676 [04438007] CMD: DATA
20:08:02.707 [04438007] RSP: 354 3.0.0 Enter data for mail with id Le0c3a02LJ82DVC
20:08:02.864 [04438007] RSP: 250 2.0.0 OK queued with id Le0c3a02LJ82DVC
20:08:02.865 [04438007] CMD: QUIT
20:08:02.896 [04438007] RSP: 221 2.0.0 smtp.strato.de closing connection
20:08:02.896 [04438007] Attempt to ip, '81.169.145.133' success: 'True'
20:08:02.913 [04438007] Process delivery status notification step from recipient success. Recipient: [lars_koeller@icloud.com], Notify: [], LastError: [], RanDomainFilter: [False], RanGlobalFilter: False
20:08:02.913 [04438007] Delivery for lars@koellers.net to lars_koeller@icloud.com has completed (Delivered)
20:08:02.914 [04438007] Removed from RemoteDeliveryQueue (0 queued or processing)
20:08:05.375 [04438007] Removing Spool message: Killed: False, Failed: False, Finished: True
20:08:05.377 [04438007] Delivery finished for lars@koellers.net at 20:08:05    [id:155004438007]
20:09:17.599 [04438008] Added to RemoteDeliveryQueue (1 queued; 0/50 processing)
20:09:17.599 [04438008] [RemoteDeliveryQueue] Begin Processing.
20:09:17.599 [04438008] Sending remote mail from lars@koellers.net

...

Sometimes the mail bounces several times and it not delivered.

DNS checked and ok.

This is new, and not seen before.

When testing via telnet smtp.strato.de 25 an issu the EHLO comman it always succeed.

Any help would be appreciated