Messages from FM flagged as spam by recipients
 

I use a fastmail alias to send/receive email. Some of the sent messages are detected as spam by recipients. The FM domain of
my alias is s e n t dot c o m.

Has this domain been blacklisted?

Is there anything I can do to prevent this from happening?

Using this common tool, I don't see any problem with the repution of the sent.com domain:
https://mxtoolbox.com/SuperTool.aspx...m&run=toolpage

I just sent a test message from my Fastmail sent.com account to Gmail, Yahoo, outlook.com, AOL, and iCloud email accounts. The test messages were all quickly delivered into the normal Inboxes. So I see no problems when testing actual popular email accounts.

Are you sure that the messages didn't have content which triggered the spam marking? Have you asked the recipients to add your email address to their online email address books?

Bill

thank you so much for your time. I did ask recipient to add me as a contact. don't know if if he ever did it.
I used the android app "Aquamail" to send the messages. after no response, I sent message again and requested a read receipt.. could read receipts trigger spam filter?

I would never add a read request. Many email systems (and recipients) will ignore the request, and the spam filter or recipient may treat the message as undesirable.

Having the same issue as of a couple days ago. Using a custom domain and suddenly everything from Fastmail is being snagged by a couple email providers as spam. Even simple messages.

Only way I was able to find out was to send an email to my work address (I'm the email admin there), and sure enough, Microsoft grabbed it before it even got to my inbox. Fastmail is saying contact Microsoft (because their spam codes are proprietary), Microsoft says contact Fastmail. Grrrrr.

Course, it's not just happening with MS recipients. It's happening with a bunch of different recipients. MS was just an example.

I haven’t noticed any problems. I just sent two test messages from my Fastmail account to my corporate work address (which uses Microsoft Exchange and their security solutions). On one message I used a From address at my Fastmail-hosted personal domain, while the other message was sent from a Fastmail-owned domain (Fastmail.com). Both arrived within a few seconds (normal delay) with no warning.

Just to be sure that some rule isn’t blocking just your address, you might try using a different From address and different subject with minimal (but not completely empty) message body when you send test messages from Fastmail.

You are using the Fastmail web interface, aren’t you? That forces the sender reputation to Fastmail IP addresses. If you use an email client there can be other issues. If you are using your own custom domain, then you need to be sure that DKIM, SPF, etc. are good. I have my domain hosted at Fastmail with DKIM and SPF set up for the Fastmail outgoing servers and DMARC set up with a strict policy (p=reject) and everything is working fine.

If the problem is only when sending from your own domain through Fastmail outgoing servers, I would check that your DKIM and SPF setup is correct and if you are using DMARC try loosening up your policy.

Bill

I don't understand, probably because my technical knowledge is very limited.

are you saying that your messages getting tagged as spam are being sent from your custom domain, meaning a domain you got from a domain registrar? or do you use a fastmail alias to send the emails?

@n5bb, I'm going to open a new thread because I don't want to hijack this one. Will edit this and post a link when I am done.

UPDATE: New thread is here: http://www.emaildiscussions.com/showthread.php?t=74642

Custom domain hosted by Fastmail. Bought the domain from Google Domains, but Fastmail was managing my DNS for the domain, so basically they were in control of everything to do with that domain for email. I'd compose an email in Fastmail and send through Fastmail using Fastmail's servers, where the email for that domain was serviced. It wasn't an alias.

understood.

I, too, have a custom domain that's set up to use fastmail dns.

but the problematic messages are ones that I've sent with an ordinary fastmail alias.

I hope they manage to help you. I'm still waiting on a response 24 hours later. Email these days is too important to wait that long for help. I didn't want to manage my own email again, but it looks like that's the road I'm going down.

Good luck.

fastmail support said they couldn't help me unless I could send them a copy of the headers of one of the messages that got caught in a spam filter, and it has to be a copy from the recipient's side. I couldn't get that because my relationship with the recipient doesn't really make it ok for me to ask for a copy from him.

I'm thinking of switching to Gmail or outlook. com

If they're using Microsoft's suite, it wouldn't matter anyway. I managed to get a copy of the headers of a received message that was stuck in MS quarantine (because I'm an admin) and Fastmail said the spam headers weren't readable. MS, meanwhile, says the issue is with Fastmail because something they do is causing the messages to be flagged as spam by MS's systems. I was hoping they could tell me why, but they can't. The fact that as soon as I went to a different email server the issue was resolved (even when sending the EXACT same email) leads me to believe Microsoft is right here. But Fastmail isn't going the extra 1/4 of a mile to help me and I really feel they should step up here, especially since I've been paying them for 15-20 years now.

I've been trying so many different email web clients over the last 24 hours or so, and none of them are ideal for how we use our email with Fastmail. I'm thinking I'll probably end up with an email client that just allows multiple IMAP collections, but I really liked that my email was actually *stored* in one location through POP so that the messages were there instantly. There is a delay with IMAP that gets really annoying. I can't find anyone who offers an option like that. The closest I came was Zoho mail, but their POP features are extremely limited.

Gmail would be close, but it's so annoying how they don't use folders, only tags. I loved how Fastmail "tamed" Gmail and made it more traditional. I tried using tags for Gmail, but it seems there's no way to keep tagged items out of your main mailbox over IMAP. They're there, AND they're in the tagged folders.

Ugh.

Would it be IP related

I'm also a 15+ year fastmail veteran. and I'm extremely disappointed with the "support" I got.

there was a time when Rob Mueller would have personally fielded my support request. and he would have made the problem go away, too.