test: Test filtermail-transport

Adds filtermail-transport tests and
a test setup for recording SMTP transactions.

Signed-off-by: Jagoda Ślązak <jslazak@jslazak.com>

filtermail/Cargo.lock

@@ -260,6 +260,17 @@ dependencies = [
  "crossbeam-utils",
 ]
 
+[[package]]
+name = "console"
+version = "0.16.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d64e8af5551369d19cf50138de61f1c42074ab970f74e99be916646777f8fc87"
+dependencies = [
+ "encode_unicode",
+ "libc",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "const-oid"
 version = "0.9.6"
@@ -465,6 +476,12 @@ version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
 
+[[package]]
+name = "encode_unicode"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34aa73646ffb006b8f5147f3dc182bd4bcb190227ce861fc4a4844bf8e3cb2c0"
+
 [[package]]
 name = "encoding_rs"
 version = "0.8.35"
@@ -559,6 +576,7 @@ dependencies = [
  "hyper",
  "hyper-rustls",
  "hyper-util",
+ "insta",
  "log",
  "lru",
  "mailparse",
@@ -567,6 +585,7 @@ dependencies = [
  "retainer",
  "rstest",
  "serde",
+ "serial_test",
  "serini",
  "testresult",
  "thiserror",
@@ -631,6 +650,17 @@ version = "0.3.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "05f29059c0c2090612e8d742178b0580d2dc940c837851ad723096f87af6663e"
 
+[[package]]
+name = "futures-executor"
+version = "0.3.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e28d1d997f585e54aebc3f97d39e72338912123a67330d723fdbb564d646c9f"
+dependencies = [
+ "futures-core",
+ "futures-task",
+ "futures-util",
+]
+
 [[package]]
 name = "futures-io"
 version = "0.3.31"
@@ -1148,6 +1178,18 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "insta"
+version = "1.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "86f0f8fee8c926415c58d6ae43a08523a26faccb2323f5e6b644fe7dd4ef6b82"
+dependencies = [
+ "console",
+ "once_cell",
+ "similar",
+ "tempfile",
+]
+
 [[package]]
 name = "ipconfig"
 version = "0.3.2"
@@ -2002,6 +2044,31 @@ dependencies = [
  "zmij",
 ]
 
+[[package]]
+name = "serial_test"
+version = "3.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "699f4197115b8a7e7ff19c9a315a4bd6fffec26cc4626ef45ecaea389e081c6d"
+dependencies = [
+ "futures-executor",
+ "futures-util",
+ "log",
+ "once_cell",
+ "parking_lot",
+ "serial_test_derive",
+]
+
+[[package]]
+name = "serial_test_derive"
+version = "3.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94e153fc76e1c6a068703d6d29c508a0b15c061c4b7e43da59cc097bc342673c"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "serini"
 version = "0.2.2"
@@ -2065,6 +2132,12 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3a9fe34e3e7a50316060351f37187a3f546bce95496156754b601a5fa71b76e"
 
+[[package]]
+name = "similar"
+version = "2.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbbb5d9659141646ae647b42fe094daf6c6192d1620870b449d9557f748b2daa"
+
 [[package]]
 name = "slab"
 version = "0.4.11"
@@ -2183,6 +2256,19 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7b2093cf4c8eb1e67749a6762251bc9cd836b6fc171623bd0a9d324d37af2417"
 
+[[package]]
+name = "tempfile"
+version = "3.27.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32497e9a4c7b38532efcdebeef879707aa9f794296a4f0244f6f69e9bc8574bd"
+dependencies = [
+ "fastrand",
+ "getrandom 0.4.2",
+ "once_cell",
+ "rustix",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "testresult"
 version = "0.4.1"