Pausing a campaign can be helpful if you ever need to tweak the campaign's content, but what happens to the schedule when this happens?
Generally speaking, Missinglettr will only re-sync a campaign's schedule if it absolutely has to. Once your campaign has been approved, Missinglettr shouldn't ever change any dates for the posts within it.
However, if you pause a campaign, a couple of scenarios could happen which would then require the schedule to be re-synced.
Scenario 1: An unsent post is now in the past
Imagine that you pause a campaign at 12pm and the next post for that campaign was due to go out at 12:15 pm. If you re-approve that campaign before 12:15 pm, then there is no need for its schedule to be re-synced and updated.
If, however, you re-approve the campaign after 12:15 pm, then we have a situation where a post needs to be sent, but its due date is now in the past. When this happens, Missinglettr will re-sync the entire schedule (of unsent posts) for that campaign to ensure that the correct gaps between each post are honoured.
Scenario 2: A newly approved campaign has taken slots from the paused campaign
If you approve an unrelated campaign in-between pausing and then re-approving a campaign, then it is possible for the time slots that the paused campaign reserved to be re-allocated to the newly approved campaign. When this happens, the re-approved campaign will always have its schedule re-synced to ensure that sending conflicts don't exist.