Questions tagged [smtp]
Simple Mail Transfer Protocol. A protocol for delivering e-mail from an end user to a server for storage and later retrieval by the intended recipient.
174 questions
5 votes
2 answers
1k views
Gmail's DMARC policy
I'm trying to understand how large email providers handle their DMARC records. I've taken a look at Gmail, and I'm a bit confused as to why they don't have a policy set for the main domain (p=none). ...
- 249
3 votes
1 answer
828 views
smtp port 465 login information compromised
I'm using gmail(and other service providers) to send out emails from port 465 which is working fine. But my login username and passwords were compromised and hackers could gain access and sent out ...
2 votes
1 answer
320 views
How should I communicate with an smtp server using socket library in Python? [closed]
I am trying to print the output of the 'HELP' command using the socket library in Python to communicate with an SMTP server, not the output of my connection to the SMTP server. That is how my Pythonic ...
- 23
0 votes
0 answers
287 views
CNAME redirection and certificate
As an experiment, I attempted to setup a CNAME for mail.mydomain.com pointing to mail.myisp.com, and using mail.mydomain.com instead of mail.myisp.com in setting up email clients connecting to that ...
- 1,297
0 votes
1 answer
261 views
metasploit smtp_enum: Testing different domain names
I'm testing my SMTP server using metasploit to see what information I can extract. Currently I'm trying to enumerate SMTP users using smtp_enum module. I've encountered a problem, the server ...
- 3
1 vote
0 answers
624 views
How secure is SMTP email today? [duplicate]
Can SMTP be relied on to send confidential information and attachments in 2023? With the concentration of email accounts in big cloud platforms belonging to Microsoft, Google and others, is email more ...
- 11
3 votes
1 answer
2k views
What are the risks of an MTA-STS policy with a long max_age?
In setting up SMTP MTA Strict Transport Security (RFC 8461) for my domain, I've noticed some contradictory advice and practice: although the maximum value for the max_age policy value is around one ...
- 33
2 votes
0 answers
199 views
Malicious Mass Email Attack Occurred, Do I Still Have Problem?
I'm using Apache Airflow and I was troubleshooting built-in smtp setup. A mass email occurred on "[email protected]". It was used as a "From:" email in a mass email attack. ...
0 votes
1 answer
435 views
SPF problems using my ISP's SMTP out-bound server
The spf record for my domain is: v=spf1 a:smtp.(my-isp).com ip4:(my-static-IP) -all I have recently added smtp.(my-isp).com to the spf record. I have sent some test emails to gmail where the outgoing ...
1 vote
2 answers
1k views
Risks sending emails with my servers using clients' SMTP credentials
Assuming I am creating an online service that allows my clients to send email (using their SMTP credentials), what risks should I consider and how to prevent them? The sender of the emails will always ...
- 55
1 vote
1 answer
1k views
Why it is so widely tolerated to allow SMTP server in DMZ to initiate connection to the LAN
I was surprised to see that the French cybersecurity agency tolerates an SMTP relay server in the DMZ (which collects emails received from the Internet) to reach the Email server in the LAN. In my ...
- 1,378
1 vote
0 answers
122 views
Bypassing Office365 Server Send As Denial [closed]
I am trying to send an e-mail via Windows Powershell ISE using Office365's hosting server, on behalf of another user which is specified in FROM part of the code using. But when I try to do this, I get:...
- 41
3 votes
2 answers
439 views
Mail gateway allowing telnet connections
Our organization is currently being tested by a IT security firm who have stated that while our internet facing mail gateway is not an open relay, they can connect to it on port 25 using telnet and ...
- 31
-1 votes
1 answer
457 views
checking if 2 emails were communicate with each other [closed]
Maybe with SMTP servers edited?
0 votes
3 answers
2k views
Sending Mail from Different Server SPF Record
Firstly, i'm not a mail expert! My workplace owns the domain example.com, until recently we had an application hosted on the LAN that worked fine and sent emails from [email protected] to various ...
- 129