E-mail on mobile

Posted on 20 January 2013

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Iphone

For my corporate mail I’m using: IMAP: linuxNN.webawere.nl with SSL on port 993.

For sending from home I would have to use SMTP: mail.zeelandnet.nl with SSL on port 465 (no need for username/password). The check of these settings is taking forever on Iphone, so be patient. I guess this is because port 465 is a legacy port and port 587 should be used.

There are two disadvantages of setting this SMTP server:

  1. This only works at home
  2. hotmail clients *sometimes* show this message “Wees voorzichtig. Deze afzender is niet goedgekeurd met onze controles voor fraudedetectie.

SPF

I guess this is due to the following header in the e-mail source:

spf=softfail (sender IP is 212.115.192.231; identity alignment result is pass and alignment mode is relaxed) smtp.mailfrom=MAILADDRESS; dkim=none (identity alignment result is pass and alignment mode is relaxed) header.d=DOMAIN; x-hmca=fail
X-AUTH-Result: FAIL
X-SID-Result: FAIL

So I checked the SPF records for the Zeelandnet SMTP server are set like this: “v=spf1 ip4:212.115.192.128/25 a:smtp-pub.zeelandnet.nl include:_senderspf.copernica.com ~all”. My domain has this spf settings in the DNS: “v=spf1 a mx ip4:SERVERIP ~all”. So I read a little further and this fail is due to my spf settings not allowing me to send e-mail through a different IP address then the one in the A record of my domain. I could try to add the IP address of the Zeelandnet SMTP server to my spf record using IP4:212.115.192.231 to solve this problem.

According to this knowledge base article, I could use mail.DOMAIN.nl without SSL on port 25. I tried it but it’s pretty slow. I’ve also had it working with a Android phone with just DOMAIN on port 587 (no SSL), but the experience is that this might not be very reliable.

Using my own server I see this header in hotmail, so this did solve my problem:

spf=pass (sender IP is IPADDRESS) smtp.mailfrom=MAILADDRESS; dkim=none header.d=DOMAIN; x-hmca=pass
X-AUTH-Result: PASS
X-SID-Result: PASS

SMTP-AUTH and TLS

I found that it’s best to set up a secure connection (TLS) and then use authentification to make sure you are you.

I ended up setting the mail.DOMAIN.nl server with SSL on port 587 with username and password, which is showing up in the message header as esmtpsa (both a secure and authenticated connection). You can also use port 465 without username and password (esmtps only, no a) but I feel that this is slower.

My webmail is using esmtpa so I guess it’s a good way to ensure your contact that it is really you that sent the e-mail. But is it really important? Both my microsoft and webmail do not show it next to the name like they show it if a DKIM signature is used. And what’s also important: is it really safe? I’m not sure yet if authentication is an added risk? 

One other thing I found is that my server acts like an open mail relay server both on port 25 and 465. As far as I understand from them is that this is not true as it checks if I’ve just logged in to my IPAM box and I guess I can check this with MXtoolbox.

Hotmail and Live

For my microsoft addresses I’m using Exchange: dub-m.hotmail.com  with SSL. It handles both incoming and outgoing e-mail.

But there is a problem with this to: if I send a message from my @live.com account to my @hotmail.nl account it passes the AUTH and SID. But when I send it the other way  (from my @hotmail.nl to my @live.com) I get a NONE on both the SPF= X-AUTH and X-SID, resulting in a message that ‘parts of the message are blocked for your safety’ and I have to unblock it to see attachments like pictures. I wonder why it is different as I’m using the exact same exchange server?

Android phone

On android I didn’t find an exchange option for my microsoft mail. So it’s setupfor incoming e-mail using pop3: pop3.live.com on port 995 with SSL (don’t delete from server).

For outgoing e-mail there is the same problem as with my corporate mail: I get spf FAIL errors. To solve this  here are the instructions for windows live SMTP settings: smtp.live.com with TLS (with credentials) on port 587. I’m using that instead.

Setting the corporate mail to TLS with credentials (esmtpsa) returns this error: Can’t make a secure connection: trust anchor for certification path not found. So I set it up with TLS (all certificates) and now it works fine. I’ll have to check this again with the servername instead of domain name, see if that helps.

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Posted in: Iphone, Office