Related to email protocols, clients, servers, content, and message format.

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1answer
28 views

relationship between anti-spam solutions and whois databases

Are there anti-spam SMTP proxies(like ASSP, qpsmtpd) or e-mail spam filtering solutions in general(like SpamAssassin) out there which create for example block filters based on objects in RIR databases?...
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2answers
87 views

Registration Email Hijacking

(Please read the update at the end) I am trying to find out how to send user registration emails securely. I read answers on this question: I don't intend to send passwords in emails, but I was ...
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1answer
28 views

Securing Web Contact Forms Against Spams

I created a web contact from with the following restrictions: An IP can send only 1 query per 8 hours. A generic text based bootstrap captcha for the form (I know this can be replaced with ...
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1answer
44 views

Rerouting emails to external account

There was a case when employee A thought he was getting legitimate emails from employee B, as the email address was valid, there were no CC/BCC addresses and just plain text in the body. Some ...
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3answers
280 views

Is sending email between different Office 365 domains (and organisations) secure?

Is sending emails between different Office 365 account owned by entirely separate entities secure? I.e. The email never leaves the Microsoft network? If the two are in the same data centre (E.g. ...
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2answers
662 views

Replay attacks and PGP email encryption

From my understanding of PGP email, the following is possible: Alice sends a message to Bob. Then Bob can take that exact same message and send to Carol while making it seem to Carol like it is from ...
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3answers
2k views

Are combined sign in / up pages dangerous, and how to improve them?

I'd like to code a combined sign in/up page like the one in the picture below. My colleague said this will allow spammers/hackers to see what email addresses are registered with our system and ...
4
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1answer
108 views

“Hacking” account when someone uses your email?

I have, on multiple occasions, received this email from Twitter: Since I have received it multiple times either this person clearly thinks the email is theirs or it's spelled similarly, something to ...
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1answer
67 views

How does my unused e-mail address get spoofed? [closed]

I have 2 e-mail accounts - one on GMail and other one on a popular mail provider in my country (O2). GMail has a secondary e-mail set for security - that is the O2. I started getting e-mails from ...
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1answer
37 views

How to properly use PGP for e-mail encryption/signature (key generation, key rollover, etc.) [duplicate]

To improve my privacy, I would like to use PGP to encrypt/sign my e-mails. How should I proceed to use PGP in a secure fashion? I am trying to think about how to do it properly. From what I found, ...
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1answer
90 views

How to deal with spam that contains my personal details?

I just noticed some spam in my inbox in GMail that is from a very suspicious e-mail address (partially redacted anonymous@webXXXXXXX.ad.aruba.it) containing a link to a similarly suspect URL (http://...
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5answers
77 views

Using an e-mail service anonymously [closed]

What are the options, to use an e-mail service anonymously without exposing yourself (your private info, name etc.) ?
3
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1answer
108 views

What happens when encrypted email is in-transit?

If you're using a service that offers end-to-end encryption, what happens when you send an email to another non-encrypted email address? Let's say I write my email in ProtonMail and then send it to a ...
3
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1answer
178 views

Has my server been compromised? (Ransomware related)

I just received an email that corresponds to the description here, which was posted just a couple of hours ago: https://myonlinesecurity.co.uk/pdfpart2-pdf-sent-from-my-samsung-galaxy-note-4-powered-...
3
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1answer
96 views

How does ProtonMail manage search?

There is a service called ProtonMail that encrypts email on the client, stores encrypted messages on their server and sends it encrypted in some fashion (depending on what email service the recipient ...
3
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2answers
128 views

Is email sent form a Java web-app over a HTTPS connection encrypted?

I'm working on a Java web-application which runs on a HTTPS connection. This application sends emails to its users. I want to protect those emails from man-in-the-middle attacks and other potential ...
3
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1answer
48 views

Does using the same mail and web server increase a risk of DDos due to IP exposure?

I use the same server for sending my emails and web hosting. I send user registration and support forum mails from my server and occasional marketing mails or newsletters. I read on a CloudFlare blog ...
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3answers
85 views

Best practices for sending tax data to and from a tax professional

I started doing business with my tax preparers when we all lived in the same city. Recently I moved to a different state. I requested that they send my "Tax Organizer" which contains some personal ...
4
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2answers
99 views

Notifying users of a possible security breach

Yesterday, a coworker informed me that a user had opened a malicious e-mail containing a .dotm document which she could not open. I undertook the usual steps to prevent the malware from spreading to ...
2
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4answers
134 views

Is it possible to fake incoming IP?

I would like to whitelist an IP address on my smtp server so that non-authenticated emails on connections originating from that IP could be routed. I control that other IP, so I can make sure that ...
2
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1answer
100 views

How does MailChimp authenticate emails?

Keeping it short, MailChimp states that: Authentication Should Be Simple Email authentication is useless if it's too hard to implement. Many email service providers require server setup in ...
2
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1answer
99 views

Cisco Registered Envelope Service (CRES), big security flaw?

While researching so called HIPAA compliant email providers, I came across Cisco Registered Envelope Service(CRES), which claims to be HIPAA compliant. According to this instruction, upon receiving ...
2
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1answer
274 views

How Risky is Paribus?

Paribus (https://paribus.co/) is a service that automatically gets money back for you if there's a price drop on a product you purchased. It seems to work by monitoring your email, to which you must ...
0
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1answer
119 views

Where email orginates [duplicate]

I keep getting emails from an unknown person. In the header file, I see this: authentication-results: spf=softfail (sender IP is 25.152.82.59) smtp.mailfrom=outlook.com; gmail.com; dkim=none (message ...
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3answers
3k views

How does a company like CloudFlare block bot crawling and email harvesters?

I saw this on CloudFlares homepage: CloudFlare protects against a range of threats: cross site scripting, SQL injection, comment spam, excessive bot crawling, email harvesters, and more. How ...
3
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1answer
196 views

Is this encrypted information? Why is it in a URL?

There's a vendor who sends us reports full of links to articles. Some of these links, especially ones that perform what I'm guessing is an HTTP verb of some kind, look like this: https://...
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5answers
3k views

Safe email validation

I have been using this RFC822-compliant regular expression for email validation. Pen testers on HackerOne have used the following horrendous email addresses which satisfy the regex: '/**/OR/**/1=1/**...
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2answers
161 views

Pin delivery: SMS, mail, or pin mailer?

Imagine a scenario where a 4-digit pincode needs to be delivered securely to an end-user. Several possibilities exists: Pin mailer (this seems to be standard according to ISO 9564-1) SMS Email Email ...
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3answers
513 views

Email unsubscribe handling security

There is another question with similar title: Unsubscribe safely however my question addresses completely another issue. I am trying to set up a notification system in the website, that will send ...
1
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0answers
156 views

Attackers on sc.imp.live.com [closed]

"Deceptive site ahead Attackers on sc.imp.live.com may trick you into doing something dangerous like installing software or revealing your personal information (for example, passwords, phone ...
3
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4answers
147 views

TLS and e-mail security

Our client has asked us to send sensitive data via TLS and to install a certificate on our mail servers so that they can verify the authenticity of our e-mails. If I understand correctly, TLS ...
1
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1answer
70 views

Distinct error messages for wrong email / password

I want to continue discussion started in this question "Username and/or Password Invalid" - Why do websites show this kind of message instead of informing the user which one was wrong? but ...
2
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1answer
58 views

Remembering email in login form

After logging out Google remembers recently used email addresses in the login form so the user only needs to enter the password. See accounts.google.com. How secure is it? What factors should I ...
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2answers
340 views

Why don't banks sign their email using S/MIME?

If email sent by my bank included S/MIME signatures that my mail client can verify, then I would have the assurance that the mail was not tampered with or sent by some malicious third-party. Most ...
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2answers
56 views

What is the purpose of this “secure mail link open in browser”

I got an email that "supposedly" was secure. It had a link which said that to get secure message follow this link. They could have verified it was me by asking my bank or my smart card to ...
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2answers
55 views

Using PGP in emails - is there to find the key?

Suppose both the receiver and sender use PGP. Suppose someone send from the sender an email and sent it to the receiver. Now he gets the content of the email at the receiver. Can he know now the keys ...
0
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2answers
65 views

Is there a way to use public mail and not to enable the provider to see its content?

I'm looking for a way to use the common public emails such as Google and Yahoo and to prevent them from reading the content of the emails either by application that scans the emails and offer ads or ...
2
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1answer
66 views

Mail from Outlook to GMX: via Yahoo? [closed]

On inspecting source of a clear scam mail I received, I noticed that the mail send from Outlook to GMX has somehow passed through Yahoo servers - how come? Is it some way to hide their original ...
0
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1answer
72 views

How can I test my spamfilter under real world conditions?

We are currently planning to migrate our outsourced mail solution to our own servers. The last thing we need to test is the spam filter. We are going to use a cloud based spam and anti virus filter ...
0
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1answer
155 views

Sites sending email using my email address

Today I was looking through my spam folder and noticed an email: The sender was myself, assume my email is xxx@gmail.com, on the from section it says xxx@gmail.com via clicktheprofits.com Does ...
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3answers
315 views

What is the simplest way to send an anonymous email?

I would like to send an email that can't be traced back to me, is there a simple direct approach to do that? I mean an electronic way that doesn't involve me going to an Internet cafe wearing a ...
1
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1answer
61 views

Is it possible to digitally sign an email twice?

User A encrypts an email with the public key of user B and digitally signs it. User B receives this message and decrypts it. B wants to forward it to user C, encrypts it with C's public key and signs ...
8
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3answers
145 views

How can you prevent email addresses from being harvested from a registration form?

When you go to a website's login form and enter the wrong credentials, the website can give you one of three error messages: Your email is wrong Your password is wrong Your email or password is ...
1
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1answer
88 views

Is the following e-mail fraud technically possible?

Summary: Can email be intercepted and modified by a 3rd-party during transit from the sender to the receiver? If so, can this interception be detected? Details: My friend (A) (mailbox at popular ...
3
votes
1answer
119 views

How to secure/cleanup my accounts after having an old email account breached

I have two email accounts. My main one that I created a few years ago and switched to, which has a very strong/unique password that is not written down or stored anywhere. It also has 2-factor auth ...
15
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3answers
2k views

Somebody is spoofing my email to send spam messages, and I have no idea how to block

Someone is using my Google Apps Email ID to send spam messages and I've received 2000+ undelivered and autorespond emails. I have no idea how to block this because the spammer is also using my email ...
0
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1answer
65 views

Where can emails be sniffed from? [duplicate]

I understand that you should not send private information in emails due, in part, to the fact that this traffic is usually unencrypted and can therefore be sniffed while in transit. Where would a ...
5
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1answer
187 views

I emailed someone a picture of a check I wrote for them. What now?

On a whim, I emailed the intended recipient of a check I wrote a picture of that filled-in check to indicate I was about to mail it out. The full front of the check, with amount, my signature, account ...
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1answer
146 views

Is it possible to prove that a forwarded email has been tampered with prior to being forwarded?

I have requested that an old email exchange between myself and HR be forwarded to me by a previous employer. They complied with the request but I suspect that the body of the exchange which they ...
3
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1answer
67 views

How Vulnerable Is An Older Version Of Outlook As An Email Application?

I am significantly displeased with some of the newer versions of Microsoft Outlook. I would prefer to continue using my older version from Office 2000 (on Windows 7 using workarounds). As a networked ...