Mailslot servers have exclusive use of three functions, as shown in the following table.
| Function | Description |
| CreateMailslot | Creates a mailslot and returns a mailslot handle. |
| GetMailslotInfo | Retrieves the maximum message size, the mailslot size, the size of the next message in the mailslot, the number of messages in the mailslot, and the amount of time a read operation can wait for a message. |
| SetMailslotInfo | Changes the read time-out for a mailslot. |
The following functions are also used by mailslot servers.
| Function | Description |
| DuplicateHandle | Duplicates the mailslot handle. |
| ReadFile | Retrieves messages from a mailslot. |
| GetFileTime | Retrieves the date and time a mailslot was created. |
| SetFileTime | Sets the date and time a mailslot was created. |