Problem with send mail to messagelabs.com

I have a problem with my email. I send email from domain probity.com.vn to sgnbooking@apl.com but they notification don't receive.

I check log from my server, messeage send success:

Nov 11 15:04:20 mail postfix/smtp[19490]: 4B9CD19009C3A: to=<sgnbooking@apl.com>, relay=cluster6.us.messagelabs.com[67.219.246.100]:25, delay=6.3, delays=0.02/0/2.9/3.3, dsn=2.0.0, status=sent (250 ok 1573459447 qp 17213 server-10.tower-384.messagelabs.com!1573459442!549642!1)

I check my IP with https://ipremoval.sms.symantec.com/ipr/lookup not delist.

Please help me!