There are multiple interresting things in this log.
Most of the attemps are attempts to log in as SMTP users on the domaine utopia-cloud.com
Was the IP of your server, already a mail server for this domain before you install smartermail ?
00:00:56.628 [45.142.195.6][5609259] Authenticating as partenaires@utopia-cloud.com
00:00:56.628 [45.142.195.6][5609259] rsp: 334 UGFzc3dvcmQ6
00:00:57.370 [45.142.195.6][5609259] Authentication failed - login failed LOGIN_FAILURE_DOMAIN_NOT_FOUND
All attempts are failing though because the domain is not configured on your server.
But it also looks like your server is accepting to relay mail to other domains without authentification, so it's or it was an open relay.
00:06:47.209 [213.142.159.176][37350199] rsp: 220 backupMX.utopia-cloud.com
00:06:47.209 [213.142.159.176][37350199] connected at 4/30/2020 12:06:47 AM
00:06:47.209 [213.142.159.176][37350199] Country code: TR
00:06:47.370 [213.142.159.176][37350199] cmd: EHLO gluepush.icu
00:06:47.373 [213.142.159.176][37350199] rsp: 250-mail2.utopia-cloud.com Hello [213.142.159.176]250-SIZE 52428800250-AUTH LOGIN CRAM-MD5250-8BITMIME250-DSN250 OK
00:06:47.555 [213.142.159.176][37350199] cmd: MAIL FROM:<norm@gluepush.icu> BODY=8BITMIME RET=HDRS
00:06:47.558 [213.142.159.176][37350199] senderEmail(1): norm@gluepush.icu parsed using: <norm@gluepush.icu>
00:06:47.563 [213.142.159.176][37350199] rsp: 250 OK <norm@gluepush.icu> Sender ok
00:06:47.563 [213.142.159.176][37350199] Sender accepted. Weight: 0.
00:07:02.458 [213.142.159.176][37350199] cmd: RCPT TO:<efrancisco@globaltextile.com.tr>
00:07:02.665 [213.142.159.176][37350199] rsp: 250 OK <efrancisco@globaltextile.com.tr> Recipient ok
00:07:13.241 [213.142.159.176][37350199] cmd: DATA
00:07:13.241 [213.142.159.176][37350199] rsp: 451 Greylisted, please try again in 240 seconds
00:07:13.241 [213.142.159.176][37350199] disconnected at 4/30/2020 12:07:13 AM
However it seems you fixed it in the meantime:
Trying 3.x.62.x...
Connected to mail2.utopia-cloud.com.
Escape character is '^]'.
220 backupMX.utopia-cloud.com
EHLO test
250-mail2.utopia-cloud.com Hello [94.103.96.117]
250-SIZE 52428800
250-AUTH LOGIN CRAM-MD5
250-8BITMIME
250-DSN
250 OK
MAIL FROM: <anyone@anywhere.com>
250 OK <anyone@anywhere.com> Sender ok
RCPT TO: <somebody@nowhere.com>
550 <somebody@nowhere.com> No such user here
EDIT: It seems it accepts mail to globaltextile.com.tr domain so I guess it is configured on your server ?
If you changed some configuration options in the meantime and the server is fresh, I would suggest to start with fresh clear logs to see if there are still issues coming after your change.
The delivery log is also important for understanding the mail flow.
What comes in for SMTP is in SMTP log, then what goes to local mailboxes or relayed to external servers with SMTP are in the delivery logs.