You sent multiple emails with attachments to the Email connector during the same sync period.
To ensure that Fivetran processes every attached file, we recommend that you adjust your Email connector’s sync frequency to match your email send rate. For example, if you send emails once every hour, you should set the sync frequency to once every hour, or faster.
When the Email connector receives an email, it copies the attached files to an internal S3 bucket so that Fivetran can process the file during the next sync period. If you send multiple emails with the same file name in either the same mail or different mails before the next sync period, Fivetran only syncs the most recent version of that file.
If you send emails in rapid succession (multiple in a span of minutes), we recommend that you confirm that each email is delivered before you send the next one. Otherwise, the emails might reach Fivetran in a different order than you intended.
If you are sending delta files as attachments, make sure that only one delta file is delivered per file name each sync period. If you send multiple emails with the same file name but different delta file values during the same sync period, we only sync the most recent file.