---
name: "CURLOPT_UPLOAD_FLAGS"
section: "3"
platform: "linux"
package: "curl"
version: "8.23.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/CURLOPT_UPLOAD_FLAGS"
---

# CURLOPT\_UPLOAD\_FLAGS(3)

upload flags for IMAP

## NAME

CURLOPT\_UPLOAD\_FLAGS - upload flags for IMAP

## SYNOPSIS

```
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_UPLOAD_FLAGS, long bitmask);
```

## DESCRIPTION

Pass a long as parameter, which is set to a bitmask, to tell libcurl which flags to send the server relating to uploaded files. The currently supported flags are:

- CURLULFLAG\_ANSWERED

  Sets the **Answered** flag for IMAP uploads. Indicates that the message has been replied to.

- CURLULFLAG\_DELETED

  Sets the **Deleted** flag for IMAP uploads. Marks the message for deletion rather than immediately removing it.

- CURLULFLAG\_DRAFT

  Sets the **Draft** flag for IMAP uploads. Marks the message as an uncompleted composition.

- CURLULFLAG\_FLAGGED

  Sets the **Flagged** flag for IMAP uploads. Marks the message for special attention.

- CURLULFLAG\_SEEN

  Sets the **Seen** flag for IMAP uploads. Marks the message as read.

## DEFAULT

A bitmask with only the **CURLULFLAG\_SEEN** flag set.

## PROTOCOLS

This functionality affects imap and imaps

## EXAMPLE

```
static size_t read_cb(char *ptr, size_t size, size_t nmemb, void *userdata)
{
  FILE *src = userdata;
  /* copy as much data as possible into the 'ptr' buffer, but no more than
     'size' * 'nmemb' bytes */
  size_t retcode = fread(ptr, size, nmemb, src);
  return retcode;
}
int main(void)
{
  CURL *curl;
  FILE *src = fopen("local-file", "r");
  if(!src)
    return 1;
  curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    curl_off_t fsize = 9876; /* set this to the size of the input file */
    /* we want to use our own read function */
    curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_cb);
    /* enable uploading */
    curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
    /* specify target */
    curl_easy_setopt(curl, CURLOPT_URL, "imap://example.com:993/mailbox");
    /* provide username */
    curl_easy_setopt(curl, CURLOPT_USERNAME, "user@example.com");
    /* provide password */
    curl_easy_setopt(curl, CURLOPT_PASSWORD, "password");
    /* specify that uploaded mail should be considered flagged */
    curl_easy_setopt(curl, CURLOPT_UPLOAD_FLAGS, CURLULFLAG_FLAGGED);
    /* now specify which pointer to pass to our callback */
    curl_easy_setopt(curl, CURLOPT_READDATA, src);
    /* Set the size of the file to upload */
    curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE, (curl_off_t)fsize);
    /* perform the upload */
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
  fclose(src);
}
```

## AVAILABILITY

Added in curl 8.13.0

## RETURN VALUE

*[curl\_easy\_setopt(3)](/curl_easy_setopt/3.md)* returns a CURLcode indicating success or error.

CURLE\_OK (0) means everything was OK, non-zero means an error occurred, see *[libcurl-errors(3)](/libcurl-errors/3.md)*.

## SEE ALSO

[**CURLOPT\_UPLOAD**(3)](/CURLOPT_UPLOAD/3.md)