Exchange degradation after roll-over to backup Internet connection

[Kathy]

Hi everyone,

Our router is configured to use a backup Internet connection in case of an
outage. Last week, we lost our circuit and we rolled over to the backup
ISP. As a result, Outlook clients started to hang during operations such as
compose, send, etc. Any idea why this was happening and how we can prevent
it?

Thanks,
Kathy