set higher level of connector logs

Exchange, , , , ,

connector logs have a rollover for log files, so if you set a high level for logging, you may have a fewer time range, but more Information

Get-ReceiveConnector | Set-ReceiveConnector -ProtocolLoggingLevel Verbose
Get-TransportService | Set-TransportService -IntraOrgConnectorProtocolLoggingLevel verbose
Get-MailboxTransportService | Set-MailboxTransportService -MailboxDeliveryConnectorProtocolLoggingLevel Verbose

for Exchange 2013