1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259
// check-if-email-exists
// Copyright (C) 2018-2022 Reacher
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
//! `check-if-email-exists` lets you check if an email address exists without
//! sending any email.
//!
//! Under the hood, it connects to the email address's SMTP server, and,
//! analyzing the server's responses against some SMTP commands, finds out
//! information about the email address, such as:
//! - Email deliverability: Is an email sent to this address deliverable?
//! - Syntax validation. Is the address syntactically valid?
//! - DNS records validation. Does the domain of the email address have valid
//! MX DNS records?
//! - Disposable email address (DEA) validation. Is the address provided by a
//! known disposable email address provider?
//! - SMTP server validation. Can the mail exchanger of the email address
//! domain be contacted successfully?
//! - Mailbox disabled. Has this email address been disabled by the email
//! provider?
//! - Full inbox. Is the inbox of this mailbox full?
//! - Catch-all address. Is this email address a catch-all address?
//!
//! ```rust
//! use check_if_email_exists::{check_email, CheckEmailInput, CheckEmailInputProxy};
//!
//! async fn check() {
//! // Let's say we want to test the deliverability of someone@gmail.com.
//! let mut input = CheckEmailInput::new(vec!["someone@gmail.com".into()]);
//!
//! // Optionally, we can also tweak the configuration parameters used in the
//! // verification.
//! input
//! .set_from_email("me@example.org".into()) // Used in the `MAIL FROM:` command
//! .set_hello_name("example.org".into()) // Used in the `EHLO` command
//! .set_smtp_port(587) // Use port 587 instead of 25
//! .set_proxy(CheckEmailInputProxy { // Use a SOCKS5 proxy to verify the email
//! host: "my-proxy.io".into(),
//! port: 1080,
//! username: None, // You can also set it non-empty
//! password: None
//! });
//!
//! // Verify this input, using async/await syntax.
//! let result = check_email(&input).await;
//!
//! // `result` is a `Vec<CheckEmailOutput>`, where the CheckEmailOutput
//! // struct contains all information about one email.
//! println!("{:?}", result);
//! }
//! ```
pub mod misc;
pub mod mx;
pub mod smtp;
pub mod syntax;
mod util;
use futures::future;
use misc::{check_misc, MiscDetails};
use mx::check_mx;
use smtp::{check_smtp, SmtpDetails, SmtpError};
use syntax::check_syntax;
use util::constants::LOG_TARGET;
pub use util::input_output::*;
/// Given an email's misc and smtp details, calculate an estimate of our
/// confidence on how reachable the email is.
fn calculate_reachable(misc: &MiscDetails, smtp: &Result<SmtpDetails, SmtpError>) -> Reachable {
if let Ok(smtp) = smtp {
if misc.is_disposable || misc.is_role_account || smtp.is_catch_all || smtp.has_full_inbox {
return Reachable::Risky;
}
if !smtp.is_deliverable || !smtp.can_connect_smtp || smtp.is_disabled {
return Reachable::Invalid;
}
Reachable::Safe
} else {
Reachable::Unknown
}
}
/// Check a single emails. This assumes this `input.check_email` contains
/// exactly one element. If it contains more, elements other than the first
/// one will be ignored.
///
/// # Panics
///
/// This function panics if `input.check_email` is empty.
async fn check_single_email(input: CheckEmailInput) -> CheckEmailOutput {
let to_email = &input.to_emails[0];
log::debug!(
target: LOG_TARGET,
"email={} Checking email \"{}\"",
to_email,
to_email
);
let my_syntax = check_syntax(to_email.as_ref());
if !my_syntax.is_valid_syntax {
return CheckEmailOutput {
input: to_email.to_string(),
is_reachable: Reachable::Invalid,
syntax: my_syntax,
..Default::default()
};
}
log::debug!(
target: LOG_TARGET,
"email={} Found the following syntax validation: {:?}",
to_email,
my_syntax
);
let my_mx = match check_mx(&my_syntax).await {
Ok(m) => m,
e => {
// This happens when there's an internal error while checking MX
// records. Should happen fairly rarely.
return CheckEmailOutput {
input: to_email.to_string(),
is_reachable: Reachable::Unknown,
mx: e,
syntax: my_syntax,
..Default::default()
};
}
};
// Return if we didn't find any MX records.
if my_mx.lookup.is_err() {
return CheckEmailOutput {
input: to_email.to_string(),
is_reachable: Reachable::Invalid,
mx: Ok(my_mx),
syntax: my_syntax,
..Default::default()
};
}
log::debug!(
target: LOG_TARGET,
"email={} Found the following MX hosts: {:?}",
to_email,
my_mx
.lookup
.as_ref()
.expect("If lookup is error, we already returned. qed.")
.iter()
.map(|host| host.exchange().to_string())
.collect::<Vec<String>>()
);
let my_misc = check_misc(&my_syntax);
log::debug!(
target: LOG_TARGET,
"email={} Found the following misc details: {:?}",
to_email,
my_misc
);
// We loop through all the MX records, and check each one of them. This is
// because to prevent SPAM, some servers put a dummy server as 1st MX
// record.
// ref: https://github.com/reacherhq/check-if-email-exists/issues/1049
let mut my_smtp: Option<Result<SmtpDetails, SmtpError>> = None;
for host in my_mx
.lookup
.as_ref()
.expect("If lookup is error, we already returned. qed.")
.iter()
{
let res = check_smtp(
my_syntax
.address
.as_ref()
.expect("We already checked that the email has valid format. qed."),
host.exchange(),
input.smtp_port,
my_syntax.domain.as_ref(),
&input,
)
.await;
let is_reachable = res.is_ok();
my_smtp = Some(res);
if !is_reachable {
continue; // If error, then we move on to next MX record.
} else {
break; // If successful, then we break.
}
}
let my_smtp = my_smtp.expect(
"As long as lookup has at least 1 element (which we checked), my_smtp will be a Some. qed.",
);
CheckEmailOutput {
input: to_email.to_string(),
is_reachable: calculate_reachable(&my_misc, &my_smtp),
misc: Ok(my_misc),
mx: Ok(my_mx),
smtp: my_smtp,
syntax: my_syntax,
}
}
/// The main function of this library: takes as input a list of email addresses
/// to check. Then performs syntax, mx, smtp and misc checks, and outputs a
/// list of results.
///
/// Please note that checking multiple emails at once (by putting multiple
/// emails in the `inputs.to_emails` Vec) is still a **beta** feature, and not
/// fully optimized. For more info, see #65
/// <https://github.com/reacherhq/check-if-email-exists/issues/65>.
pub async fn check_email(inputs: &CheckEmailInput) -> Vec<CheckEmailOutput> {
if inputs.to_emails.len() > 1 {
log::warn!(
target: LOG_TARGET,
"Verifying multiple emails with this library is still a beta feature, please don't overuse it. See reacherhq/check-if-email-exists #65."
);
}
// FIXME Obviously, the below `join_all` is not optimal. Some optimizations
// include:
// - if multiple email addresses share the same domain, we should only do
// `check_mx` call for all these email addresses.
// - if multiple email addresses share the same domain, we should call
// `check_smtp` with grouped email addresses, to share a SMTP connection.
// ref: https://github.com/reacherhq/check-if-email-exists/issues/65.
let inputs = inputs.to_emails.iter().map(|email| {
// Create n `CheckEmailInput`s, each with one email address.
CheckEmailInput {
to_emails: vec![email.clone()],
from_email: inputs.from_email.clone(),
hello_name: inputs.hello_name.clone(),
proxy: inputs.proxy.clone(),
retries: inputs.retries,
smtp_port: inputs.smtp_port,
smtp_security: inputs.smtp_security,
smtp_timeout: inputs.smtp_timeout,
yahoo_use_api: inputs.yahoo_use_api,
}
});
future::join_all(inputs.map(check_single_email)).await
}