This function fetches all the structured information for a given message. The optional flags parameter only has a single option, FT_UID, which tells the function to treat the msg_number argument as a UID. The returned object includes the envelope, internal date, size, flags and body structure along with a similar object for each mime attachement. The structure of the returned objects is as follows:
Table 1. Returned Objects for imap_fetchstructure()
| type | Primary body type |
| encoding | Body transfer encoding |
| ifsubtype | TRUE if there is a subtype string |
| subtype | MIME subtype |
| ifdescription | TRUE if there is a description string |
| description | Content description string |
| ifid | TRUE if there is an identification string |
| id | Identification string |
| lines | Number of lines |
| bytes | Number of bytes |
| ifdisposition | TRUE if there is a disposition string |
| disposition | Disposition string |
| ifdparameters | TRUE if the dparameters array exists |
| dparameters | An array of objects where each object has an "attribute" and a "value" property corresponding to the parameters on the Content-disposition MIMEheader. |
| ifparameters | TRUE if the parameters array exists |
| parameters | An array of objects where each object has an "attribute" and a "value" property. |
| parts | An array of objects identical in structure to the top-level object, each of which corresponds to a MIME body part. |
See also: imap_fetchbody().