Email messages that are sent are not received

People are not receiving the emails that I send and I am uncertain how long it has been going on. If I send these same people emails from the same account using thunderbird, they will receive the emails so I do not think it is my email being flagged.

Sending an email to myself using k-9 mail works. k9mail) However, sending email to numerous accounts ( gmail, yahoo etc)
are not received nor are they found in spam or trash folders. These test emails do show up in my sent folder which I verify on my PC using Thunderbird. I did a quick comparison of the settings I have in thunderbird and they seem to be the same.

Smtp server
[Checked ] required sign-in
No client certificate

I tried changing my password and that did not have any effect.

When I checked the outbox, it is empty

Using version K-9 Mail 6.2 (just updated)
in “outgoing mail settings” clicking next does not produce any errors.

Any ideas?
(Really like K-( mail and have been using it for a long time. Thanks for such a great app)

Welcome to the forum @Kit .

Have you tried disabling Settings > Privacy > Hide hostname ?

If you search the forum, you will find that some users have reported issues. Their providers do not accept “localhost” or “” or any local address as sender. Rather than throwing an error, they just swallow the email and it’s lost in the provider’s ether.

Thanks. I went to privacy and all I saw was a setting to hide mail client. I sent a test email to a gmail account and it was not received.

I searched the forum and found this thread. I am going through it now. 5.8 showing as sent, but not always arriving at destination - #2 by cketti

This also does not exist for me. Do you use a modified K9 version?

@tchara I am wondering if there is some way to get this menu option as all I have under privacy is “hide mail client”
and use UTC time

I don’t have that option either on v6.201 :woman_shrugging:

Yeah, forgot that I merged the old 5.6 menu code snippet into the current build. Sorry.

Since 5.700/5.800, with the standard build, the option is no longer available.

@tchara I see. I am running 6.2 I am not so sure that this setting will fix things. But do you know if it will be added? After reading the other thread I linked to above. It seems like if I need to send email from my android I might need to abandon using K-9. I did reach out to the hosting company that I also use for email and the tech did not seem to see there was a possible issue in how their server was handling emails sent with the K-9 app.

I would like very much to be able to continue using k-9 mail.

The problem is with the providers who don’t adhere to the standards. @cketti is trying to make a point by insisting on standard conformity in the K-9 implementation…

Whether that is a good path to follow or not shall be judged by other people. I for my part only think that this ideological battle should have been fought 15 years ago. Today, the train has inevitably left the station and no one is doing anybody any favours this way…

Long story short answer: Either you switch email apps (Nine, R2Mail2, etc.pp.), modify K-9 and compile your own fork, or your provider changes their attitude. Guess what is the most taken path by normal users…

Yes, trying to use standards whereever it is possible is good approach. But if there is an easy and known workaround for situations like this I always would vote for an additional option.

@tchara thank you.

I have to admit much of this is going over my head. I am trying to explain this to a mail service provider’s tech support and it would help if I could more precisely explain what is (likely) happening. What standard are the providers not adhering to?

Is it the standard to accept "localhost " or “” etc? I do not have the understanding or terminology to get tech support to find the problem.

Is the reason why they do not accept these because typically spammers do that? K-9 does this so that emails do not leak one’s ip address right?

1 Like

The corresponding standard nowhere specifies that local IP addresses are prohibited. Further, whenever an email is rejected, dropped or not delivered for whatever reason, the sender has to be notified.

Your provider just drops emails with local IP addresses “for spam protection”. That is not a technical reason to drop an email.