[root@router postfix]# cat  /var/log/maillog | grep 195.214.192.100
May 23 18:43:33 router postfix/smtp[1802]: F0C7027D884: to=<tkachenko_ov@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=1, status=bounced (host mxs.ukr.net[195.214.192.100] said: 550 Sender verify failed (in reply to RCPT TO command))
May 23 19:04:53 router postfix/smtp[2672]: 597B127D884: to=<azhu@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=0, status=bounced (host mxs.ukr.net[195.214.192.100] said: 550 Sender verify failed (in reply to RCPT TO command))
May 25 13:17:04 router postfix/smtp[32745]: 83E2D27D884: to=<azhu@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=0, status=bounced (host mxs.ukr.net[195.214.192.100] said: 550 Sender verify failed (in reply to RCPT TO command))
May 25 13:33:12 router postfix/smtp[893]: CCE3D27D884: to=<tkachenko_ov@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=1, status=bounced (host mxs.ukr.net[195.214.192.100] said: 550 Sender verify failed (in reply to RCPT TO command))
May 25 13:36:02 router postfix/smtp[913]: 4F24A27D884: to=<tkachenko_ov@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=0, status=bounced (host mxs.ukr.net[195.214.192.100] said: 550 Sender verify failed (in reply to RCPT TO command))
May 26 10:48:52 router postfix/smtp[15389]: 71F8127D884: to=<tkachenko_ov@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=0, status=bounced (host mxs.ukr.net[195.214.192.100] said: 550 Sender verify failed (in reply to RCPT TO command))
May 26 10:49:46 router postfix/smtp[15389]: 1F1CE27D884: to=<tkachenko_ov@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=0, status=bounced (host mxs.ukr.net[195.214.192.100] said: 550 Sender verify failed (in reply to RCPT TO command))
May 26 16:50:33 router postfix/smtp[30150]: 322F327D884: to=<ponomarchuk_m@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=0, status=sent (250 OK id=1QPb6w-0004dI-CK)
May 26 16:59:19 router postfix/smtp[31859]: C55EB27D884: to=<ponomarchuk_m@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=1, status=sent (250 OK id=1QPbFP-000NB3-Se)
May 26 17:05:46 router postfix/smtp[32452]: 3368D27D884: to=<ponomarchuk_m@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=0, status=sent (250 OK id=1QPbLf-000HFR-9S)
May 26 17:06:43 router postfix/smtp[32692]: 9635227D884: to=<ponomarchuk_m@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=0, status=sent (250 OK id=1QPbMa-0003VF-Mx)
May 26 17:11:30 router postfix/smtp[953]: ADEA227D884: to=<ponomarchuk_m@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=0, status=sent (250 OK id=1QPbRD-000LvG-P7)
May 26 17:17:53 router postfix/smtp[1155]: 661A627D884: to=<ponomarchuk_m@ukr.net>, relay=mxs.ukr.net[195.214.192.100], delay=0, status=bounced (host mxs.ukr.net[195.214.192.100] said: 550 Sender verify failed (in reply to RCPT TO command))