Mails can't be delivered from Powershell through Haproxy

Hello! Could you help me, please?

When Powershell script sends an email message through Haproxy, the message doesn’t reach the destination mailbox. In Haproxy logs:

Apr 13 23:10:04 vmls-haproxy2 haproxy[932]: [13/Apr/2022:23:10:04.611] fe_mail_smtp fe_mail_smtp/ws-ms2 1/0/216 681 CD 2903/1/0/0/0 0/0
Apr 14 23:10:04 vmls-haproxy2 haproxy[117538]: [14/Apr/2022:23:10:04.436] fe_mail_smtp fe_mail_smtp/ws-ms2 1/0/268 681 CD 1140/1/0/0/0 0/0

In the documentation, “CD” means
C : the TCP session was unexpectedly aborted by the client.
D : the session was in the DATA phase.

If SMTP traffic goes directly to mail server, all is working correctly.

At the same time, other programs don’t have any problems with sending messages through Haproxy:

Apr 18 11:36:42 vmls-haproxy1 haproxy[339204]: [18/Apr/2022:11:36:31.794] fe_mail_smtp fe_mail_smtp/ws-ms2 1/0/10546 2554 -- 1682/1/0/0/0 0/0
Apr 18 11:36:52 vmls-haproxy1 haproxy[339204]: [18/Apr/2022:11:36:42.346] fe_mail_smtp fe_mail_smtp/ws-ms1 1/0/10612 2554 -- 1691/1/0/0/0 0/0
Apr 18 11:37:12 vmls-haproxy1 haproxy[339204]: [18/Apr/2022:11:37:01.779] fe_mail_smtp fe_mail_smtp/ws-ms3 1/0/10517 2554 -- 1720/1/0/0/0 0/0

My SMTP config in haproxy.cfg:

listen fe_mail_smtp
  mode tcp
  bind :25
  option tcplog
  balance leastconn
  option redispatch
  retries 3
  timeout client 5m
  timeout server 5m
  timeout connect 5s
  server ws-ms1 check
  server ws-ms2 check
  server ws-ms3 check

Why does it happen and what can be done to fix the problem with Powershell? Maybe, add or modify some options to SMTP listen section?