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Questions tagged [email]

The server configuration of email, including POP3, SMTP, IMAP, and popular server software packages that control email.

The server configuration of email, including POP3, SMTP, IMAP, and popular server software packages that control email.

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Why an empty MAIL FROM address can sent out email?

We are using Smarter Mail system. Recently, we found that hacker had hacked some user accounts and sent out lots of spams. We have firewall to ratelimit the sender, but for the following email, the firewall couldn't do this because of the empty FROM…
garconcn
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Setting up a fake email address to trap spammers

I have heard it suggested that we set up a special email address, with it's only purpose being to be harvested. Then blacklisting every sender that targets this address. I'm wondering: if anyone else has tried this how do you go about doing it (ie…
Brent
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Does the email size limit include the size of the body?

(If there is a better place to ask this, let me know.) A lot of email servers limit the combined size of files attached to incoming emails. Like, for example, maybe some email server disallows messages larger than 20MB; it would fail if an…
Mathew Alden
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Get cron to send html-formatted emails

I have a stats program which runs on log files via cron. The stats program can output HTML. Right now I rely on the MAIL_TO mechanism in the crontab. MAILTO=my@email.addr 55 23 * * * /usr/bin/htmlstats The problem is that I want the email sent to…
Mark L
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How does DKIM work when sending emails from multiple sources/servers?

So if I'm understanding DKIM correctly, it basically is a public/private key type of service. However, how does this work if you send emails from multiple servers/sources? For instance, I have a split domain where I send some emails (under the…
Marc NJ
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Problem with Postfix

I have Postfix installed and Sendmail is not running. I try to send mail using mail but the following warning comes up and the mail doesn't get sent: postdrop: warning: unable to look up public/pickup: No such file or directory This is also…
Chetan
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Is port 25 used between mail servers secured with SSL/TLS?

Does port 25(smtp) used by MTAs work under plain text/non-encrytion ? I couldn't find any resources that state smtp with 25 by default is plain text. From Opportunistic_TLS (See the code section S: ...) , it…
Rick
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Repairing e-mail "domain reputation" on google?

Google's gmail has recently started marking all mail from domain example.com (real domain name is hidden) as spam, with grey-box explanation of: "Why is this message in spam? Lots of messages from example.com were identified as spam in the…
Matija Nalis
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How important are PTR records for Email Servers?

Does anyone know of any studies done to show how much email will be rejected if there is not ptr record for the SMTP banner name of an email server? Are reverse checks always done when enabled, or is it sometimes configured so if an spam program…
Kyle Brandt
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What good Active Directory + Exchange competition is there?

Based on this question regarding enhanced permission support in filesystems, what is the best permissions + directory and mail stack to compare against Active Directory on NTFS with Exchange? I'm familiar with OpenLDAP for directory services, and…
warren
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How can the `to:` and `delivered-to:` fields in an email i received be different?

I received an email and I noticed that the Delivered-To: and To: fields were different. The To: field is not my actual email address, but the Delivered-To: field is. How does this happen? Delivered-To: mike.smith@work.com To: "msmith@work.com"…
asdf
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MX records, better setup for load balancing and failover

Take domain example.com, it has two mail servers mail1.example.com and mail2.example.com, both already configured, usually I would go with the following setup: example.com. 1200 IN MX 10 mail1.example.com. example.com. …
Krdan
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Simple Mail System for Ubuntu?

What I'm looking for should be relatively easy. All I want to do is setup something VERY small for Ubuntu that will allow me to use the mail() function in PHP from my web server (/var/www/). I don't want anything complex. I have a…
willbeeler
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Does "~all" in the middle of an SPF record signal the end of the record when it is parsed?

Our company's SPF record format is as follows: "v=spf1 include:_spf.google.com ~all a mx ip4:X.X.0.0/23 include:spf.example.com ?all" So we have an "~all" in the middle of our SPF record. On the openspf.com website, they say this regarding the "all"…
whelanska
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Have a valid SPF record but still can spoof my email

I have set up an SPF record for my domain, but I still can spoof email-addresses for my domain using fake email services like this one: http://deadfake.com/Send.aspx The email does arrive to my gmail inbox just fine. The email does have SPF errors…
jitbit
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