The Post Office says it expects some disruption to mail deliveries this week as Royal Mail's national strike goes ahead.
Action on Thursday and Friday means mail posted in the Isle of Man on Wednesday should be delivered as normal the following day, but any posted on Thursday it will be delayed by at least 24 hours.
Isle of Man Post says mail posted on Friday could be held up because of backlogs.
Special delivery next day guarantee mail will be suspended on Thursday and Friday, and the knock-on effects could mean disruption until next Monday.
Customers with any queries can contact the Customer Services Team on 664664.
Isle of Man Post Office employees are not involved in the industrial action.