sendmail outbound-only? (Debian 10)

I finally realized that my WordPress install is not sending emails, and presumably it's because outbound port 25 is blocked by Linode since late 2019; I gather you have to submit a request to open it.

Before I do that, I want to make sure sendmail is locked down to only handle these sorts of locally-generated outbound emails and not accept any connections from outside.

I've been searching and reading, here and on Google, for awhile now and only feeling more overwhelmed than I should be, so I figured I'd ask here.

Presume, at least for the time being, that I'm not looking for "install a different MTA" answers, and literally looking for how to do this under sendmail.


1 Reply

Linode Staff

Hey there -

Once we've removed the mail filters, and you have access to port 25 you should be able to send emails.

Locking down sendmail is a separate issue entirely. As I'm not an expert myself, I also did some Googling to see what I could find for you. I found this page, which gives you some direction for configuring sendmail, that might be helpful to you:

Sendmail Config

I've also added some additional tags to try and boost this post's visibility for you and get it in front of some of our mail server experts.


Please enter an answer

You can mention users to notify them: @username

You can use Markdown to format your question. For more examples see the Markdown Cheatsheet.

> I’m a blockquote.

I’m a blockquote.

[I'm a link] (

I'm a link

**I am bold** I am bold

*I am italicized* I am italicized

Community Code of Conduct