Tagged Questions

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

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14
votes
3answers
2k views

How does Bayesian poisoning work?

This answer mentions Bayesian poisoning in passing and I've read the wikipedia page but don't feel I've fully grasped it. The first case, where a spammer sends a spam with a payload (link, malicious ...
1
vote
1answer
28 views

Tracking sender of Email via email address ONLY

Is there a way to track the sender and the location via the email address only. The problem is somebody has created a similar sounding email id to send content to my official circle with a view to ...
1
vote
3answers
90 views

Potential risks when sending plain text E-Mails with encrypted attachments?

To ensure privacy in communication I encrypt and sign E-Mails using gpg4win. However, sometimes the communication does not work as expeceted (GPGTools and Outlook/gpg4win seem to be incompatible). In ...
2
votes
1answer
106 views

TLS library problem when connecting to Dovecot

I have a Comodo PositiveSSL certificate issued for mail.btcontract.com and I've set up Postfix and Dovecot to work with it in the following way: Postfix main.cf: smtpd_tls_cert_file = ...
1
vote
2answers
59 views

Viruses From Email Attachments

My company just got a worm. The specific one is beside the point, but I linked a couple pages that I think describe the worm / virus below. We're getting lots of emails to Outlook asking us to open ...
-5
votes
1answer
74 views

Is this email from Liliane Bettencourt a scam? [closed]

I received the following email from someone claiming to be the second-richest woman in the world, Liliane Bettencourt. I, Liliane authenticate this email, you can read about me on: ...
1
vote
1answer
70 views

Is it possible to restrict email accounts within one computer?

can emails(e.g gmail)can be configured to open-up only in my laptop ,my operating system is windows 8 and is it possible to restrict my gmail account to be opened up only in my computer?Usually we ...
6
votes
2answers
193 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 ...
5
votes
1answer
179 views

Is email encryption, as claimed by ProtonMail, possible?

Is it possible to create a Web service that encrypts all messages, such that only the writer, and the person to whom the mail is sent, can read it? In other words, is the theory behind ProtonMail ...
1
vote
1answer
78 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
55 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
55 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
314 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
68 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 ...
-6
votes
1answer
55 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 ...
0
votes
1answer
51 views

Security implications for email address and url changes?

recently, we are seeing some From:, To:, Cc: addresses being rewritten from user1@companyA.com to: ...
1
vote
3answers
57 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 ...
1
vote
1answer
125 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 ...
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
176 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
94 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 ...
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
41 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 ...
1
vote
2answers
1k views

Based on these email headers, where is this virus coming from?

I'm seeing a virus in our network with some strange headers. Sometimes they are coming (sourced) from a netscaler VIP, other times they seem to come from an Exchange hub server. How do I determine ...
1
vote
2answers
79 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 ...
27
votes
10answers
6k views

How to explain to a customer that spamfilters don't catch everything

I used to work in a small office which provided basic desktop support for users. One day I had to answer a call from a very angry customer and he asked for my boss. He wanted to know how could one ...
5
votes
1answer
455 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
49 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 ...
1
vote
3answers
69 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 ...
3
votes
1answer
71 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
1answer
30 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 ...
1
vote
0answers
39 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 ...
1
vote
2answers
98 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 ...
3
votes
2answers
68 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 ...
3
votes
0answers
42 views

Opening mail from IMAP with no risk for the user

I'm building a website for an association. Its aim is to, out of other thing, provide an easy mail manager to communicate with the member, stored in a database. This database is always up to date as ...
1
vote
1answer
52 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 ...
4
votes
8answers
420 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
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 ...
5
votes
4answers
815 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 ...
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 ...
0
votes
0answers
46 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 ...
2
votes
3answers
57 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
2answers
55 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 ...
26
votes
3answers
2k views

Tell people that I can encrypt emails

I know that it is still not very easy to use PGP for an average user. However, the situation is improving (there are some easy plugins that can even nicely integrate into your GMail webmail). In ...
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
143 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
1answer
359 views

How to report abuse spam with X-AntiAbuse header which was added to track abuse?

I've received the following spam e-mail (with the link to viagra site): Return-Path: <silviani@server04.funet.co.il> Received: from server04.funet.co.il (server04.funet.co.il. [212.29.215.70]) ...
0
votes
0answers
38 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
433 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
233 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 ...