Change log for PROOFPOINT_MAIL

Date Changes
2024-08-14 Enhancement:
Mapped "xmailer" to "security_result.detection_fields".
2024-08-13 Enhancement:
- When "threats.classification" is "toad", then mapped "threats.classification" to "security_result.category_details".
2024-07-30 Enhancement:
- Added a new Grok pattern to parse a new format of SYSLOG logs.
2024-07-16 Enhancement:
- Changed mapping of "metadata.event_timestamp" from "msg.messageTime" to "clicks.threatTime".
- Mapped "msg.messageTime" to "additional.fields".
2024-05-27 Enhancement:
- Mapped "msg.policyRoutes" to "additional.fields".
2024-04-03 Enhancement:
- Extracted "sender_domain" from "msg.fromAddress" and "clicks.sender", and mapped to "principal.domain.name".
- Mapped "clicks.sender" to "principal.user.email_addresses".
- Mapped "clicks.recipient" to "target.user.email_addresses".
2023-06-26 Enhancement -
- Mapped "clicks.threatStatus" to "security_result.threat_status".
2022-11-03 Enhancement - Added condition check for date field .
"give the higher priority to the date which has maximum timestamp".
if "click_time" > "threat_time" date mapped to click_time else threat_time.
2022-07-13 Enhancement - Modified the mapping for "intermediary.user.email_addresses" from "(messagesBlocked|messagesDelivered).*toAddresses" to "(messagesBlocked|messagesDelivered).*ccAddresses" .
2022-06-29 Enhancement - Added gsub to remove '<>' from the fields 'clicks.messageID' and 'm' mapped to 'network.email.mail_id'.
2022-05-25 Mapped "messageSize" to "additional" field.
Mapped "campaignID" to "security_result.rule_id" field.
Mapped "ccAddresses" to "intermediary.user.email_addresses" field.
Mapped "toAddresses" to "target.user.email_addresses" field.