You might find the attachments are being stripped from some email entering your organization despite recipient and sender domain have been added to the "whitelist" in Sender ID Agent. Agents on Exchange Edge server are as follows: Each of the agents has its own priority, meaning which of the agent will be first, second, third,... in line to filter. Filters take precedence over another just in case spam is found. For example: If Connection Filtering Agent finds spam (connection verification fails) it discards the message and none is processed any further. If the message passes Connection Filtering Agent it then goes to Address Rewriting Inbound Agent , which is next on priority list etc. So, if we put a recipient to BypassedRecipients list in Sender ID Agent , it will be bypassed only for Sender ID Agent filter and not for example Attachment Filtering Agent. As per Microsoft. " The BypassedRecipients parameter specifies one or more SMTP email address...
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