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

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6
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2answers
212 views

Have both my email address and IP been spoofed, or has someone gotten my password, or…?

Just examined a spam email sent to me. The header's "originator" has both my email address and my web site's IP address, (my SMTP). My first thought is that someone has obtained my email password ...
2
votes
1answer
1k views

How to secure my network, laptop, ipad and email accounts which are possibly hacked?

Background Last month I noticed lots of failed emails in my inbox and after few minutes I lost my access to my Yahoo Mail. My friends informed me that they have received spam emails from me. So I ...
1
vote
1answer
84 views

help identifying an IP address from email sent from my gmail account

Someone sent the following email from my gmail account. I believe it was hacked and if I can find the IP address I may be able to identify the person who did it. Here is the information. Please let me ...
-1
votes
1answer
67 views

How is PKI used to encrypt an e-mail for multiple recipients?

My understanding is that when an e-mail is encrypted and sent to a recipient, the recipient's public key is used to encrypt the e-mail, and then only the recipient can decrypt it with their private ...
1
vote
1answer
64 views

Spam Mail - have someone broke in to my shared hosting account? [duplicate]

Yesterday I noticed that one of my e-mail addresses (the only one within that domain) started to receive a lot of weird messages that the mail haven't reach the target (something like "Sorry, Qmail ...
2
votes
2answers
360 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 ...
2
votes
1answer
98 views

Wrapping my head around Protonmail

I've been trying to grasp how Protonmail could work. From what it gather, it works like this: When you signup, you create an account password and a mailbox password. A PGP private/public key pair is ...
5
votes
1answer
273 views

How is ZixCorp able to provide email encryption without a password?

I am trying to understand how/if an email I received is being encrypted. A financial institution sent me a verifiable email (i.e. not phising) asking me to fill out a pdf form to complete a ...
-6
votes
1answer
60 views

Email obfuscation/munging recent research [closed]

Does anyone know of any recent (past year or two) research into email obfuscation/munging? All I can find are tests done five to ten years ago. I'm trying to decide whether it's something still ...
2
votes
3answers
78 views

Postfix master running as root

Does running /usr/lib/postfix/master as a root could cause a security threat ? A fresh installation, gives this : root 11622 0.0 0.0 4792 1432 ? Ss 19:11 0:00 ...
5
votes
5answers
11k views

Email headers from messages sent via Gmail online client contain private IP addresses. What are these addresses?

Someone has sent a sensitive email from my Gmail account. I wanted to trace the IP address by checking out the Received: by X field in the header of the sent message. However, every message that is ...
1
vote
1answer
173 views

Email clients and POODLE vulnerabilities

I use a commercial email service that provides IMAP over SSL on port 993 and SMTP over SSL on port 465. I currently connect to their servers with Thunderbird and the Apple's iOS8 email client. Could ...
1
vote
2answers
88 views

E-mail tracking countermeasures

I've started using Sidekick to know when an email is opened or one of the links in it is clicked. What I ask now is how to know if an email I received is provided with a similar tracking system. With ...
12
votes
2answers
1k views

Should I change phone number and e-mail address after PayPal fraud?

I have been the victim of PayPal fraud. I hadn't used PayPal in a year and then within 9 days there were three unauthorized transactions on my account for a total of 150 Canadian dollars and 290 ...
-1
votes
3answers
263 views

Gmail, Yahoo, Hotmail , and so on; How do they check the content of an attached password-protected archived file like Winrar?

How is it possible that mailing systems like Gmail, Yahoo, and Hotmail are able to check the content of an attached password-protected archived file like WINRAR, if the password cannot be guessed, ...
1
vote
2answers
108 views

How can one verify that two separate emails are not coming from the same place?

I sell merchandise online. Due to suspicious activity (in my very amateur opinion), I have reason to believe that, what seems like two separate orders, are actually a single scam being perpetrated by ...
2
votes
3answers
4k views

Someone keeps using my email address. What to do?

I have had a GMail ever since it was created, so it's an email address that is easy to remember, but also easy for somebody else to get confused with. Since I'm not going to post my email address ...
5
votes
3answers
1k views

How does someone with HubSpot Sidekick knows when I opened their sent email?

This app claims to know when recipients opened the emails that were sent to them. Tracking clicked URLs is fairly straightforward. What I don't understand is how a 3rd party can possibly know when I ...
1
vote
2answers
51 views

PKI expired and renewed, do my correspondents have to do anything?

My PKI certificate (Digital ID for email from Symantec, issuer is "VeriSign Client External Certification Authority - G3") expired after 1 year and so I have renewed it. Do the people I correspond ...
3
votes
2answers
196 views

How do web email clients store my passwords from other providers?

The situation comes down to this: When I enter in hotmail, it retrieves my messages connecting to other providers: they could only do so by using my email and password. Since I had signed in a ...
5
votes
1answer
466 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 ...
1
vote
2answers
52 views

Having a consistent “dont reveal email addresses of members” policy [duplicate]

Developers are dogmatic on having "invalid username or password" on login screens; our applications should not reveal if somebody is a member given an email address. But there are two other ways our ...
2
votes
4answers
2k views

How to check if range of IP addresses are SPAM blacklisted?

While it's easy to check if a single IP address is blacklisted for SPAM using for example http://www.spamcop.net/bl.shtml, then is there a way to check multiple addresses at once? For example how to ...
3
votes
1answer
90 views

How to sign and encrypt mail using openssl?

I am trying to send and encrypt mail using openssl. So far, I figure I should use theese commands: cat ${content} | \ openssl smime -encrypt -inkey lib/me.crt -aes256 -subject "$titre (cs)" -to ...
1
vote
3answers
70 views

How safe is it for an app to trust a click on a link in an email?

In my question and answer application, Joe signs up, logs in and adds a question. He then shares the question via email to his trusted friends. How safe is it to provide a link within that app ...
1
vote
1answer
35 views

PCI Compliance for attachment in email

I am wondering if they are any PCI compliance issues around users of a service sending email with attachments that may or may not contain sensitive information through said service? As an example, if ...
5
votes
4answers
1k 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 ...
10
votes
4answers
3k views

How do I encrypt the source and destination IP address, along with various parts of an email?

If the subject makes no sense to you, that's fine, it makes no sense to me. I've been tasked with securing emails sent from some devices, and I'm looking for advice on intelligent questions to ask to ...
4
votes
8answers
519 views

Is it possible to prove a certain email has been sent using a certain computer?

I can understand that an SMS can be traced to the mobile phone which it has originated from and the phone owner has no chance in court but to claim that someone else has used his phone but what about ...
1
vote
2answers
101 views

Unexpected emails have been sent - do I need to wipe my Android?

A few days ago I received a Notification from my Android saying that it could not send mail because an attachment was too large. I opened my Gmail App and found 5 messages in the Sent Mail folder ...
1
vote
0answers
40 views

Using email to authorize access to a user's account

would greatly appreciate some advice from the experts here on this stackexchange. I'm building an application that requires access to a user's resources from a 3rd party application. This 3rd party ...
3
votes
2answers
69 views

How do I respond to a spam server that invalidates my tokens? [duplicate]

Our web application sends a one-time use generated token, in the form of an URL, to clients who forget their passwords. This works except for the case where the client is sitting behind another server ...
9
votes
4answers
2k views

Good, simple list of reasons that email is inherently insecure

I've been searching for a while, trying to find a good get of information about the inherent risks of transmitting sensitive data via email. I'm really looking for a comprehensive list of all the ...
1
vote
1answer
62 views

How to share sensitive documents with unknown/untrusted parties?

My exact use case is that I'm starting a new job, and I need to transmit sensitive personal documents to support my application. However, the same applies for applying for a loan, buying a house etc ...
1
vote
4answers
314 views

Is e-mail sent from a Gmail address to another Gmail address encrypted?

Gmail provides an SSL connection and also encrypts the entire session by default. But if you send a mail, once it leaves gmails servers, it can be read at any point on the internet. But what about ...
1
vote
1answer
21 views

Can I keep large encrypted files in my mailbox on mail provider server?

Is there any restriction or policy of large e-mail providers (such as GMail, Yahoo, Hotmail and similar) for keeping/storing large encrypted files by the users within their disk quota in 3rd party ...
2
votes
1answer
3k views

What is cleardot.gif next to the senders signature in Gmail? [closed]

I am concerned that my computer has been compromised because I sent an email out - but now I noticed that there is a link in the email I did not insert, and I am worried I have a virus or something. ...
4
votes
4answers
410 views

Exchange 2013 blocks txt file attachments - are there security reasons?

My Exchange Admin is setting up 2013, and it is set to block txt file attachments specifically (as well as others). I have tried searching for risks associated with txt attachments but could not ...
30
votes
2answers
3k views

Is email less secure than voicemail, snail mail, or internet portals for transferring sensitive information?

Where I am in the US, health care providers refuse to send anything through email (e.g. even something as trivial as an appointment reminder). Often they claim that email is not secure. Instead they ...
2
votes
3answers
69 views

Email account 'hacked'; do I need to regenerate my server's DKIM _domainkey?

I'm just learning about DMARC (DKIM/SPF), so I apologize if my question doesn't make sense. A few days after I installed a DMARC policy on my server I noticed that the reports from yahoo.com ...
3
votes
6answers
15k views

Possible ways to track down anonymous mail senders?

In my previous post here How can I send emails anonymously? the community framed and guided how we can send an anonymous emails through various ways which makes me thought about the following things ...
0
votes
0answers
60 views

Is this login flow via an authenticated email account safe?

I want to have users log in by entering an email, and then proving that they control that email. I only care that they do control the email, and so want to avoid add another password to the process if ...
9
votes
5answers
2k views

When registering for most websites, why do you need to confirm your email address?

I'm working on a site which allows users to sign up for a service. They choose a username/password, enter their personal details, etc and proceed into the site, their details being stored for future ...
-3
votes
2answers
59 views

Does company email can access hangouts and private emails? [duplicate]

I'am curious whether the administrator's has the privilege to access the hangouts chat and the email of employees? For example, here in our company we are using the gmail as our private email ...
2
votes
2answers
133 views

It it a good idea to whitelist inbound email using a Hash on the address? (Similar to BATV, but with DKIM)

Problem Statement I'm looking at ways to ensure that business partners, or emails from trusted senders, never get quarantined; ....in other words prevent "ham being seen as spam". Ideally this ...
2
votes
1answer
49 views

Preventing users abusing emailing feature of web application

Our web application offers users with the option to bulk email a bunch of interesting information to multiple email addresses at once. It's fairly easy to register an account with the service and thus ...
-4
votes
1answer
183 views

Trace email without header or IP address [closed]

I have a gmail address only. It is a copy of the email. I do not have the original email. Is there anyway to trace it?
0
votes
0answers
53 views

What does proxyexec + cagefs.server mean in the e-mail X-Source-Args?

I've the following headers in the e-mail which I've received as spam: X-Source: X-Source-Args: /usr/sbin/proxyexec -q -d -s /var/run/proxyexec/cagefs.sock/socket /bin/cagefs.server X-Source-Dir: ...
4
votes
2answers
619 views

How can I prevent my E-mail address from being used as the sender for fraudulent/scam messages?

Recently, me and at least one other person I know received an obvious scam E-mail that starts off something like this: We considered your resume to be very attractive and we thought the vacant ...
2
votes
2answers
380 views

Will using a self-signed SSL certificate on a mail server hinder communication?

According to this ArsTechnica article, using a self-signed certificate on a mail server is a bad idea: When we set up a Web server in our previous series, getting SSL/TLS working was a ...