Commit | Line | Data |
---|---|---|
0756eb3c PH |
1 | TRANSPORTS: |
2 | ||
3 | A delivery attempt results in one of the following values being placed in | |
4 | addr->transport_return: | |
5 | ||
6 | OK success | |
7 | DEFER temporary failure | |
8 | FAIL permanent failure | |
9 | PANIC disaster - causes exim to bomb | |
10 | ||
11 | The field is initialized to DEFER when the address is created, in order that | |
12 | unexpected process crashes or other problems don't cause the message to be | |
13 | deleted. | |
14 | ||
15 | For non-OK values, additional information is placed in addr->errno, | |
16 | addr->more_errno, and optionally in addr->message. These are inspected only if | |
17 | the status is not OK, with one exception (see below). | |
18 | ||
19 | In addition, the addr->special_action field can be set to request a non-default | |
20 | action. The default action after FAIL is to return to sender; the default | |
21 | action after DEFER is nothing. The alternatives are: | |
22 | ||
23 | SPECIAL_NONE (default) no special action | |
24 | SPECIAL_FREEZE freeze the message | |
25 | SPECIAL_WARN send warning message | |
26 | ||
27 | The SPECIAL_WARN action is the exception referred to above. It is picked up | |
28 | only after a *successful* delivery; it causes a warning message to be sent | |
29 | containing the text of warn_message to warn_to. It can be used in appendfile, | |
30 | for example, to send a warning message when the mailbox size crosses a given | |
31 | threshold. | |
32 | ||
33 | If the transport is handling a batch of several addresses, it may either put an | |
34 | individual value in each address structure, and return TRUE, or it may put a | |
35 | common value in the first address, and return FALSE. | |
36 | ||
37 | Remote transports usually return TRUE and local transports usually return | |
38 | FALSE; however, the lmtp transport may return either value, depending on what | |
39 | happens inside it. | |
40 | ||
41 | **** |