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

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9
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6answers
2k views

POP3/IMAP Stronger Authentication

We recently deployed a two-factor-authentication solution in order to strength logon to our web applications (one of them is web based mail, Microsoft outlook web access) Most of the users who have ...
9
votes
2answers
126 views

Best practices when forwarding an email or copy / pasting from confidential information sources?

I get asked this a lot from older people, or for legal matters. They want to forward an email message they've received to another party, while removing any identifying information from the first party ...
9
votes
3answers
889 views

How did the spammers get this address?

A few months ago I configured a test mail server on Amazon AWS, all legit. I used a new address to my catchall-domain (something similar to, but not exactly, ...
8
votes
6answers
5k views

How can I send emails anonymously?

How can I send email anonymously? We used to track email's IP and its location based upon the email headers, and there are many possible ways to track the email's id's which were sent by the anonymous ...
8
votes
2answers
6k views

How to prove my Gmail has been hacked?

I believed that someone had hacked my Gmail because they were using information contained within my emails in an attempt to try to convince me that they were psychic. I told them that I didn't believe ...
8
votes
3answers
589 views

Does OpenPGP encryption mean that not even I can see my data?

Say I have an email and I want to send it to someone else. I encrypt it with his public key. This ensures that only he can read my message. Does this also means that I won't be able to read it? If so, ...
8
votes
4answers
465 views

Next steps after webmail account was compromised

John Doe told me the following story: I got a mail from a good friend. It just contained a single link. That seemed odd but I didn't think a lot about it. After clicking on the link, the web site ...
8
votes
6answers
782 views

Security of email [duplicate]

Possible Duplicate: How commonly are SSL/TLS or S/MIME used by e-mail providers? Say, Alice uses gmail and Bob uses hotmail. Alice wants to send an email to Bob. Alice goes to gmail ...
8
votes
5answers
921 views

E-mail can be made to appear like it came from a big organization?

I know almost nothing about security. So, please bear with me if the questions sound silly. Is it possible for a malicious person to make an e-mail appear as if it came from a big company like ...
8
votes
3answers
250 views

Is it enough to look at the sender's email address?

I use Gmail. When I receive an email, Gmail displays the sender's email address. So far I've always looked at this address when receiving sensitive mails, to avoid phishing. For example, I know by ...
8
votes
2answers
610 views

How to safely display html emails like gmail does it?

I'm building a webmail, which must be able to display html emails. But how to prevent xss and similiar attacks, while not loosing html formatting? In gmail, when I receive some emails from, lets say, ...
8
votes
3answers
1k views

Can my ISP read my gmail even when using HTTPS? Is there a way to prevent that?

Can my ISP read my gmail or other email even when using HTTPS? I guess they can do that since they are the "man-in-the-middle". Is there a way to prevent that? This is related to the news that in ...
8
votes
2answers
806 views

“Secure” third-party inbox

My business sometimes receives emails from our clients that are sent through a "secure" third-party inbox. The client send the message through this third-party service. The third party creates an ...
8
votes
2answers
2k views

Can a firewall tamper with email attachments?

I am using Thunderbird as an email client for managing my different email accounts. Yesterday my friend sent me an email with a PDF attachment. Today when I tried to open the attachment I get the ...
8
votes
3answers
124 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 ...
8
votes
2answers
824 views

ProtonMail security concerns

This TED talk brought me here. First of all, to those who created ProtonMail: Nice job!!. Regardless of what people say, it's definitely a big step forward from tradition options like Hotmail, Gmail ...
8
votes
4answers
7k views

How can hackers guess passwords (using dictionary attack or brute force) without being locked out?

Nowadays almost every website you want to register in; is asking you to create a complicated password...But why cant we use simple passwords? I am just wondering because in case of multiple wrong ...
8
votes
1answer
599 views

Protecting emails in your database

It's common to encrypt passwords in the database, but I'm wondering what solutions are out there to protect emails in your database. Not just from hacking, but from disgruntled employees or engineers ...
8
votes
3answers
2k views

PHP mail() Header Injection Prevention

This site nicely explains the problem. Essentially, nearly all php mail() examples that are given are vulnerable to header injection attacks. The referenced site gives a regex sanitation solution ...
8
votes
2answers
2k views

Do any Exchange hardening guidelines recommend disabling OWA Webready? Should they?

For the fourth time in over a year, Exchange OWA has put our internal network at risk due to a remote code execution flaw that exists on the server runtime. This risk is compounded by the fact ...
7
votes
3answers
608 views

Is it secure to have an “email no longer available” feature on your registration form?

I was just implementing a new feature on the registration form of my site that checks if an email address is still available to register an account with. I am wondering if it is secure to show a user ...
7
votes
3answers
22k views

How to Stop Email Spoofing [closed]

Apart from SPF, what else can be done to stop hackers from spoofing your company's email addresses?
7
votes
5answers
2k views

Privacy issues with email providers [closed]

I am looking for an email provider (or for a way to do it myself) that will not divulge my personal information under no circumstances. I found out that getting this information with a order for ...
7
votes
3answers
428 views

Is DKIM needed for emails encrypted with OpenPGP?

DKIM seems to prove that a message came from where it claims to be from. However, OpenPGP encrypts the entire email and signs it which obviously proves it also came from the person it says it did. ...
7
votes
3answers
518 views

How Reliably do mail systems transmit Encrypted PDFs

We have an solution design that will be sending Encrypted PDF's to our many clients, who will all be using varied email providers. We have tested the pdf's through the usual cast of internet mail ...
7
votes
2answers
508 views

Is personal email hosting really secure?

One of my friends has his own personal email hosting. Let's assume for the sake of argument that it is "secure", meaning that no third party can read the emails in his server either through hacking or ...
7
votes
2answers
366 views

Is a mail secure if it's PGP-encrypted, but unsigned when sent with DKIM?

I run my own mail server and would like to use different addresses on the same domain. If I were to sign mails from those addresses, I'd have to generate new PGP keys for each and every one of them. ...
7
votes
4answers
435 views

How can I convince my communication partner to use encryption in everyday life?

The latest developments made it very clear, how easily basically all communication channels can be wiretapped. However, I think most people still ignore this fact. Especially in business most ...
7
votes
2answers
3k views

If I send an email over SSL, will it always be transmitted over SSL?

This is largely a question of how MTAs and different components communicate. I'm curious that if I send an email using SMTP over SSL to my MTA, can it's next jump to the next MTA or MDA be insecure? ...
7
votes
1answer
3k views

Email SSL security?

I use IMAP and I only access my email through SSL. However, the settings for encrypted email access seem a bit more complicated that https. Can someone explain the security implications of the ...
7
votes
3answers
11k views

Is it possible for a phishing link to install a major virus on a Mac?

My girlfriend recently had her university MS Exchange account hacked. The attacker took over her email account and started using it to send thousands of spam emails. After a while, her email account ...
7
votes
3answers
83 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 ...
7
votes
1answer
203 views

What's the best duration for storing e-mail? [closed]

We’ve all become so accustomed to using email in our daily personal and working lives that we really don’t give a whole lot of thought to it. It’s the fastest way to communicate with others in the ...
7
votes
2answers
2k views

secure webmail provider

Which email providers (e.g. Gmail, Yahoo, etc) offer the most robust security for a personal email account? The recent article about Mat Honan getting hacked illustrates the challenge. The account ...
7
votes
1answer
365 views

Fake email messages via List-Unsubscribe header

List-Unsubscribe email header makes it possible to recipient to automatically unsubscribe from the mailing list: List-Unsubscribe: <mailto:list@host.com?subject=unsubscribe&body=qwe> Free ...
7
votes
2answers
7k views

Yahoo mail hacked - how to recover, how did it happen and how to prevent?

I was yesterday informed by some friends that they received spam mails with my name as sender. The sender addresses look like firstnamelastname@spacepc.pt and firstnamelastname@revistaplot.com with ...
6
votes
3answers
316 views

How do I securely exchange server logins with remote developers?

I work for a virtual organization (we're all remote) that uses a lot of freelancers/subcontractors. Very often I need to exchange SSH login information with developers working on projects for us. How ...
6
votes
5answers
1k views

Is storing plaintext passwords for email accounts any less bad? [duplicate]

I recently found out that the company I use for shared hosting stores passwords for email accounts in plaintext (they mentioned this to me incidentally, while troubleshooting another issue). They're a ...
6
votes
6answers
7k views

How did the spam email sender get my name?

Some time ago I bought something online from a reputable website. I paid through my credit card and everything worked fine. The thing which is important to note is that the name used on the credit ...
6
votes
2answers
2k views

spam with my own domain

At my work we have a very tricky issue with spam. We use postfix, and recently began to receive several spams mail with our own domain. This is obviously very prejudicial for us, because many ...
6
votes
5answers
974 views

How do spammers verify the validity of a huge amount of email addresses?

I noticed that there is an email address validation method, that is to telnet to a email MX server and send rcpt command to the server. But for this method, the MX server may abort connection after ...
6
votes
4answers
347 views

Circumventing a “freemail” account form filter

I'll be honest - I want to download a free PDF from a website which requires me to enter my "non freeware" email address. I do have them, but I dont want to use one as I'm afraid of landing up on a ...
6
votes
4answers
4k views

How should I react to finding GMail outbox e-mails that I didn't send?

This morning I found 17 e-mails in my GMail outbox that I didn't send. The e-mails were sent to seemingly random people from my GMail contacts and contained the link to a suspicious php file on ...
6
votes
1answer
2k views

is it possible to sniff email content inside network?

I am working in a IT company. I am using LAN for all internet activities. I send some email from my personal gmail account. My network administrator sniffed all email I send from LAN and he shows the ...
6
votes
4answers
283 views

Technical security issues with proactively executing a phishing campaign targeting your own users

We've had some issues with compromised accounts due to users falling victim to phishing campaigns. The possibility of us doing a phishing campaign against our own users to proactively shame them has ...
6
votes
2answers
1k views

Can someone know my IP address through Thunderbird email attachments?

Can someone know my IP address through Thunderbird email attachments? Can a cunning attacker manage to find my IP address through attachment 'images' in emails that I unsuspectingly open?
6
votes
4answers
2k views

Email header IP address

Do the IP addresses in an email header include information from the device from which the mail is being sent, or from the mail server?
6
votes
3answers
2k views

How to prove someone sent an email to you?

There are similar question about how to prove YOU sent an email, but I want to know if it is possible to prove a 3rd party sent an email to me. An individual sent some very threatening emails to my ...
6
votes
7answers
2k views

Is PGP combined with a regular web-based email service secure?

With the disappearance of private email services like Lavabit and Tormail (http://www.dailydot.com/news/email-anonymous-hushmail-lavabit-nsa/) it seems that we will need to resort back to standard ...
6
votes
3answers
919 views

Two-Factor Authentication: When is it worth it?

I was reading this article, and it triggered the question: Why not use two factor authentication? In his case, it both possibilities were enabled anyway, so this looks to me like it's two attack ...