I run my own mail server and I can see from the logs that two emails sent from TCBD this morning were both received by my server at 9:50 ET.
The trade matching email notification was generated by TCDB at 9:39:49 ET and sent to its outgoing mail server at 9:39:57 ET. The transaction message notification was generated by TCDB at 9:45:04 ET and sent to the outgoing mail server 9 seconds later.
I just sent a test message to myself on TCDB at 4:30pm ET and it was sent to the outgoing mail relay server 19 seconds later. It didn't arrive on my server until 4:50pm ET
So looks like there is a delay on the sending server, either by configuration or unintentionally.
Not sure if the :50 arrival time is coincidental.