Member email doesn't work and is "bad" when checked

New member email is not working.
Per the Email Address Checker:
"Member Michael Madden, CC, ALB michael.madden@se.com Bad"
This is on accelorators.toastmastersclubs.org
Member reports that on another club's Free Toast Host server, his email address got changed to some strange string of characters and had to be corrected. (I don't know the identify of the other club.)
This email address is not on our websites black list.
this email works outside of Free Toast Host. This is the member's company email address of Schneider Electric a French corporation.
Member was able to authenticate with email ... successfully 30 days ago.
Need assistance to make this email address work correctly

His company is using messagelabs.com as their spam filter, they are very zealous about stopping unidentified email.

He will need to request that server@toastmastersclubs.org and agenda@toastmastersclubs.org are added to their white list.

I have removed the email from the bounce log and he is now receiving email

Jul 22 12:57:37 toastmastersclubs sendmail[10077]: x6MCvaUJ010073: to=<michael.madden@se.com>, ctladdr= (501/502), delay=00:00:01, xdelay=00:00:01, mailer=esmtp, pri=121181, relay=cluster3.eu.messagelabs.com. [46.226.53.51], dsn=2.0.0, stat=Sent (ok 1563800257 qp 31857 server-14.tower-303.messagelabs.com!1563800256!86312!1)