diff --git a/Cargo.lock b/Cargo.lock
index 4b586d4..d558dd9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,67 +1,100 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aho-corasick"
+version = "0.7.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cc936419f96fa211c1b9166887b38e5e40b19958e5b895be7c1f93adec7071ac"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "base64"
 version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b25d992356d2eb0ed82172f5248873db5560c4721f564b13cb5193bda5e668e"
 dependencies = [
- "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "byteorder",
 ]
 
 [[package]]
 name = "byteorder"
 version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a7c3dd8985a7111efc5c80b44e23ecdd8c007de8ade3b96595387e812b957cf5"
 
 [[package]]
 name = "cfg-if"
 version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
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 [[package]]
 name = "charset"
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 dependencies = [
- "base64 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "encoding_rs 0.8.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "base64",
+ "encoding_rs",
 ]
 
 [[package]]
 name = "email"
 version = "0.1.0"
 dependencies = [
- "mailparse 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mailparse",
+ "regex",
 ]
 
 [[package]]
 name = "encoding_rs"
 version = "0.8.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
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 dependencies = [
- "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if",
 ]
 
 [[package]]
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 dependencies = [
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- "quoted_printable 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "base64",
+ "charset",
+ "quoted_printable",
 ]
 
+[[package]]
+name = "memchr"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
+
 [[package]]
 name = "quoted_printable"
 version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "86cedf331228892e747bb85beb130b6bb23fc628c40dde9ea01eb6becea3c798"
 
-[metadata]
-"checksum base64 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0b25d992356d2eb0ed82172f5248873db5560c4721f564b13cb5193bda5e668e"
-"checksum byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a7c3dd8985a7111efc5c80b44e23ecdd8c007de8ade3b96595387e812b957cf5"
-"checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
-"checksum charset 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4f426e64df1c3de26cbf44593c6ffff5dbfd43bbf9de0d075058558126b3fc73"
-"checksum encoding_rs 0.8.20 (registry+https://github.com/rust-lang/crates.io-index)" = "87240518927716f79692c2ed85bfe6e98196d18c6401ec75355760233a7e12e9"
-"checksum mailparse 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)" = "51a60bad00d8aa905d31cf239f207ad4ef16c963ea53cf522d5fd7dc7f3ecfe2"
-"checksum quoted_printable 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "86cedf331228892e747bb85beb130b6bb23fc628c40dde9ea01eb6becea3c798"
+[[package]]
+name = "regex"
+version = "1.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e076559ef8e241f2ae3479e36f97bd5741c0330689e217ad51ce2c76808b868a"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "456c603be3e8d448b072f410900c09faf164fbce2d480456f50eea6e25f9c848"
diff --git a/Cargo.toml b/Cargo.toml
index 9087fa5..e7fa65e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,3 +8,4 @@ edition = "2018"
 
 [dependencies]
 mailparse = "0.9.2"
+regex = "1.7.0"
diff --git a/src/main.rs b/src/bin/mailparse.rs
similarity index 100%
rename from src/main.rs
rename to src/bin/mailparse.rs
diff --git a/src/bin/printable.rs b/src/bin/printable.rs
new file mode 100644
index 0000000..996ae03
--- /dev/null
+++ b/src/bin/printable.rs
@@ -0,0 +1,27 @@
+use std::{io, io::Read};
+
+use regex::Regex;
+
+fn main() -> io::Result<()> {
+    let re = Regex::new("[^[[:print:]]\n]").expect("invalid regex");
+    let mut buffer = String::new();
+    io::stdin().read_to_string(&mut buffer)?;
+    let buffer = re.replace_all(&buffer, "");
+
+    let mut last_c = 0;
+    for l in buffer.lines() {
+        let c = l
+            .as_bytes()
+            .iter()
+            .filter(|b| match b {
+                b' ' | b'\t' => false,
+                _ => true,
+            })
+            .count();
+        if !(c == 0 && last_c == 0) {
+            println!("{l}");
+        }
+        last_c = c;
+    }
+    Ok(())
+}