| 1 | .TH dot-qmail 5 |
| 2 | .SH NAME |
| 3 | dot-qmail \- control the delivery of mail messages |
| 4 | .SH DESCRIPTION |
| 5 | Normally the |
| 6 | .B qmail-local |
| 7 | program delivers each incoming message to your system mailbox, |
| 8 | .IR homedir\fB/Mailbox , |
| 9 | where |
| 10 | .I homedir |
| 11 | is your home directory. |
| 12 | |
| 13 | It can instead |
| 14 | write the mail to a different file or directory, |
| 15 | forward it to another address, |
| 16 | distribute it to a mailing list, |
| 17 | or even execute programs, |
| 18 | all under your control. |
| 19 | .SH "THE QMAIL FILE" |
| 20 | To change |
| 21 | .BR qmail-local 's |
| 22 | behavior, set up a |
| 23 | .B .qmail |
| 24 | file in your home directory. |
| 25 | |
| 26 | .B .qmail |
| 27 | contains one or more lines. |
| 28 | Each line is a delivery instruction. |
| 29 | .B qmail-local |
| 30 | follows each instruction in turn. |
| 31 | There are five types of delivery instructions: |
| 32 | (1) comment; (2) program; (3) forward; (4) mbox; (5) maildir. |
| 33 | .TP 5 |
| 34 | (1) |
| 35 | A comment line begins with a number sign: |
| 36 | |
| 37 | .EX |
| 38 | # this is a comment |
| 39 | .EE |
| 40 | |
| 41 | .B qmail-local |
| 42 | ignores the line. |
| 43 | .TP 5 |
| 44 | (2) |
| 45 | A program line begins with a vertical bar: |
| 46 | |
| 47 | .EX |
| 48 | |preline /usr/ucb/vacation djb |
| 49 | .EE |
| 50 | |
| 51 | .B qmail-local |
| 52 | takes the rest of the line as a command to supply to |
| 53 | .BR sh . |
| 54 | See |
| 55 | .B qmail-command(8) |
| 56 | for further information. |
| 57 | .TP 5 |
| 58 | (3) |
| 59 | A forward line begins with an ampersand: |
| 60 | |
| 61 | .EX |
| 62 | &me@new.job.com |
| 63 | .EE |
| 64 | |
| 65 | .B qmail-local |
| 66 | takes the rest of the line as a mail address; |
| 67 | it uses |
| 68 | .B qmail-queue |
| 69 | to forward the message to that address. |
| 70 | The address must contain a fully qualified domain name; |
| 71 | it must not contain extra spaces, angle brackets, or comments: |
| 72 | |
| 73 | .EX |
| 74 | # the following examples are WRONG |
| 75 | .br |
| 76 | &me@new |
| 77 | .br |
| 78 | &<me@new.job.com> |
| 79 | .br |
| 80 | & me@new.job.com |
| 81 | .br |
| 82 | &me@new.job.com (New Address) |
| 83 | .EE |
| 84 | |
| 85 | If the address begins with a letter or number, |
| 86 | you may leave out the ampersand: |
| 87 | |
| 88 | .EX |
| 89 | me@new.job.com |
| 90 | .EE |
| 91 | |
| 92 | Note that |
| 93 | .B qmail-local |
| 94 | omits its new |
| 95 | .B Return-Path |
| 96 | line when forwarding messages. |
| 97 | .TP 5 |
| 98 | (4) |
| 99 | An |
| 100 | .I mbox |
| 101 | line begins with a slash or dot, |
| 102 | and does not end with a slash: |
| 103 | |
| 104 | .EX |
| 105 | /home/djb/Mailbox.sos |
| 106 | .EE |
| 107 | |
| 108 | .B qmail-local |
| 109 | takes the entire line as a filename. |
| 110 | It appends the mail message to that file, |
| 111 | using |
| 112 | .BR flock -style |
| 113 | file locking if possible. |
| 114 | .B qmail-local |
| 115 | stores the mail message in |
| 116 | .I mbox |
| 117 | format, as described in |
| 118 | .BR mbox(5) . |
| 119 | |
| 120 | .B WARNING: |
| 121 | On many systems, |
| 122 | anyone who can read a file can |
| 123 | .B flock |
| 124 | it, and thus hold up |
| 125 | .BR qmail-local 's |
| 126 | delivery forever. |
| 127 | Do not deliver mail to a publicly accessible file! |
| 128 | |
| 129 | If |
| 130 | .B qmail-local |
| 131 | is able to lock the file, but has trouble writing to it |
| 132 | (because, for example, the disk is full), |
| 133 | it will truncate the file back to its original length. |
| 134 | However, it cannot prevent mailbox corruption if the system |
| 135 | crashes during delivery. |
| 136 | .TP 5 |
| 137 | (5) |
| 138 | A |
| 139 | .I maildir |
| 140 | line begins with a slash or dot, |
| 141 | and ends with a slash: |
| 142 | |
| 143 | .EX |
| 144 | /home/djb/Maildir/ |
| 145 | .EE |
| 146 | |
| 147 | .B qmail-local |
| 148 | takes the entire line as the name of a directory in |
| 149 | .I maildir |
| 150 | format. |
| 151 | It reliably stores the incoming message in that directory. |
| 152 | See |
| 153 | .B maildir(5) |
| 154 | for more details. |
| 155 | .PP |
| 156 | If |
| 157 | .B .qmail |
| 158 | has the execute bit set, |
| 159 | it must not contain any |
| 160 | program lines, |
| 161 | .I mbox |
| 162 | lines, |
| 163 | or |
| 164 | .I maildir |
| 165 | lines. |
| 166 | If |
| 167 | .B qmail-local |
| 168 | sees any such lines, |
| 169 | it will stop and indicate a temporary failure. |
| 170 | |
| 171 | If |
| 172 | .B .qmail |
| 173 | is completely empty (0 bytes long), or does not exist, |
| 174 | .B qmail-local |
| 175 | follows the |
| 176 | .I defaultdelivery |
| 177 | instructions set by your system administrator; |
| 178 | normally |
| 179 | .I defaultdelivery |
| 180 | is |
| 181 | .BR ./Mailbox , |
| 182 | so |
| 183 | .B qmail-local |
| 184 | appends the mail message to |
| 185 | .B Mailbox |
| 186 | in |
| 187 | .I mbox |
| 188 | format. |
| 189 | |
| 190 | .B .qmail |
| 191 | may contain extra spaces and tabs at the end of a line. |
| 192 | Blank lines are allowed, but not for the first line of |
| 193 | .BR .qmail . |
| 194 | |
| 195 | If |
| 196 | .B .qmail |
| 197 | is world-writable or group-writable, |
| 198 | .B qmail-local |
| 199 | stops and indicates a temporary failure. |
| 200 | .SH "SAFE QMAIL EDITING" |
| 201 | Incoming messages can arrive at any moment. |
| 202 | If you want to safely edit your |
| 203 | .B .qmail |
| 204 | file, first set the sticky bit on your home directory: |
| 205 | |
| 206 | .EX |
| 207 | chmod +t $HOME |
| 208 | .EE |
| 209 | |
| 210 | .B qmail-local |
| 211 | will temporarily defer delivery of any message to you |
| 212 | if your home directory is sticky |
| 213 | (or group-writable or other-writable, |
| 214 | which should never happen). |
| 215 | Make sure to |
| 216 | |
| 217 | .EX |
| 218 | chmod -t $HOME |
| 219 | .EE |
| 220 | |
| 221 | when you are done! |
| 222 | It's a good idea to test your new |
| 223 | .B .qmail |
| 224 | file as follows: |
| 225 | |
| 226 | .EX |
| 227 | qmail-local -n $USER ~ $USER '' '' '' '' ./Mailbox |
| 228 | .EE |
| 229 | .SH "EXTENSION ADDRESSES" |
| 230 | In the |
| 231 | .B qmail |
| 232 | system, |
| 233 | you control all local addresses of the form |
| 234 | .IR user\fBBREAK\fIanything , |
| 235 | as well as the address |
| 236 | .I user |
| 237 | itself, |
| 238 | where |
| 239 | .I user |
| 240 | is your account name. |
| 241 | Delivery to |
| 242 | .I user\fBBREAK\fIanything |
| 243 | is controlled by the file |
| 244 | .IR homedir/\fB.qmail\-\fIanything . |
| 245 | (These rules may be changed by the system administrator; |
| 246 | see |
| 247 | .BR qmail-users (5).) |
| 248 | |
| 249 | The |
| 250 | .B alias |
| 251 | user controls all other addresses. |
| 252 | Delivery to |
| 253 | .I local |
| 254 | is controlled by the file |
| 255 | .IR homedir/\fB.qmail\-\fIlocal , |
| 256 | where |
| 257 | .I homedir |
| 258 | is |
| 259 | .BR alias 's |
| 260 | home directory. |
| 261 | |
| 262 | In the following description, |
| 263 | .B qmail-local |
| 264 | is handling a message addressed to |
| 265 | .IR local@domain , |
| 266 | where |
| 267 | .I local |
| 268 | is controlled by |
| 269 | .BR .qmail\-\fIext . |
| 270 | Here is what it does. |
| 271 | |
| 272 | If |
| 273 | .B .qmail\-\fIext |
| 274 | is completely empty, |
| 275 | .B qmail-local |
| 276 | follows the |
| 277 | .I defaultdelivery |
| 278 | instructions set by your system administrator. |
| 279 | |
| 280 | If |
| 281 | .B .qmail\-\fIext |
| 282 | doesn't exist, |
| 283 | .B qmail-local |
| 284 | will try some default |
| 285 | .B .qmail |
| 286 | files. |
| 287 | For example, |
| 288 | if |
| 289 | .I ext |
| 290 | is |
| 291 | .BR foo-bar , |
| 292 | .B qmail-local |
| 293 | will try first |
| 294 | .BR .qmail-foo-bar , |
| 295 | then |
| 296 | .BR .qmail-foo-default , |
| 297 | and finally |
| 298 | .BR .qmail-default . |
| 299 | If none of these exist, |
| 300 | .B qmail-local |
| 301 | will bounce the message. |
| 302 | (Exception: for the basic |
| 303 | .I user |
| 304 | address, |
| 305 | .B qmail-local |
| 306 | treats a nonexistent |
| 307 | .B .qmail |
| 308 | the same as an empty |
| 309 | .BR .qmail .) |
| 310 | |
| 311 | .B WARNING: |
| 312 | For security, |
| 313 | .B qmail-local |
| 314 | replaces any dots in |
| 315 | .I ext |
| 316 | with colons before checking |
| 317 | .BR .qmail\-\fIext . |
| 318 | For convenience, |
| 319 | .B qmail-local |
| 320 | converts any uppercase letters in |
| 321 | .I ext |
| 322 | to lowercase. |
| 323 | |
| 324 | When |
| 325 | .B qmail-local |
| 326 | forwards a message as instructed in |
| 327 | .B .qmail\-\fIext |
| 328 | (or |
| 329 | .BR .qmail-default ), |
| 330 | it checks whether |
| 331 | .B .qmail\-\fIext\fB-owner\fP |
| 332 | exists. |
| 333 | If so, |
| 334 | it uses |
| 335 | .I local\fB-owner@\fIdomain |
| 336 | as the envelope sender for the forwarded message. |
| 337 | Otherwise it retains the envelope sender of the original message. |
| 338 | Exception: |
| 339 | .B qmail-local |
| 340 | always retains the original envelope sender |
| 341 | if it is the empty address or |
| 342 | .BR #@[] , |
| 343 | i.e., if this is a bounce message. |
| 344 | |
| 345 | .B qmail-local |
| 346 | also supports |
| 347 | .B variable envelope return paths |
| 348 | (VERPs): |
| 349 | if |
| 350 | .B .qmail\-\fIext\fB-owner\fP |
| 351 | and |
| 352 | .B .qmail\-\fIext\fB-owner-default\fP |
| 353 | both exist, it uses |
| 354 | .I local\fB\-owner\-@\fIdomain\fB-@[] |
| 355 | as the envelope sender. |
| 356 | This will cause a recipient |
| 357 | .I recip\fB@\fIreciphost |
| 358 | to see an envelope sender of |
| 359 | .IR local\fB\-owner\-\fIrecip\fB=\fIreciphost\fB@\fIdomain . |
| 360 | .SH "ERROR HANDLING" |
| 361 | If a delivery instruction fails, |
| 362 | .B qmail-local |
| 363 | stops immediately and reports failure. |
| 364 | .B qmail-local |
| 365 | handles forwarding after all other instructions, |
| 366 | so any error in another type of delivery will prevent all forwarding. |
| 367 | |
| 368 | If a program returns exit code 99, |
| 369 | .B qmail-local |
| 370 | ignores all succeeding lines in |
| 371 | .BR .qmail , |
| 372 | but it still pays attention to previous forward lines. |
| 373 | |
| 374 | To set up independent instructions, |
| 375 | where a temporary or permanent failure in one instruction |
| 376 | does not affect the others, |
| 377 | move each instruction into a separate |
| 378 | .B .qmail\-\fIext |
| 379 | file, and set up a central |
| 380 | .B .qmail |
| 381 | file that forwards to all of the |
| 382 | .BR .qmail\-\fIext s. |
| 383 | Note that |
| 384 | .B qmail-local |
| 385 | can handle any number of forward lines simultaneously. |
| 386 | .SH "SEE ALSO" |
| 387 | envelopes(5), |
| 388 | maildir(5), |
| 389 | mbox(5), |
| 390 | qmail-users(5), |
| 391 | qmail-local(8), |
| 392 | qmail-command(8), |
| 393 | qmail-queue(8), |
| 394 | qmail-lspawn(8) |