Does IP affect mail deliverability?

Question

gmail

When sending from a mobile device through a client app like Spark or Canary, does my device's IP address affect mail deliverability?

IMHO, I began to notice this effect.
Someone can explain?

Answer 1

I don’t know how Spark or Canary work, I never used it, but I used the SMTP protocol.

• gmail.com is very reluctant to deliver emails from private smtp servers even (with configured DKIM, SPF, etc.), only from reputable and well-known ones. Therefore, after dancing, I abandoned the idea of ​​\u200b\u200braising my smtp server.
  
• gmail.com generally delivers via the web interface much more readily and reliably than from the smtp client. For smtp clients there are subtleties of adjustment. Addresses, ports and SSl/TLS requirements change periodically.
  
• Of course the smtp server knows the IP address of the client that is accessing it. This is the first command in the exchange after the smtp handshake - `EHLO 100.500.000.000` And if the server has reason to consider the address unreliable, it may well stop communicating on this.
  There's a good reason for all of this -- smtp is an ancient, weakly secure protocol developed in the old days when the internet was friendly. Today, to protect against smtp attacks and abuse, servers without protocol guarantees introduce artificial restrictions.
  

Answer 2

The IP from which you send mail via SMTP (for example, the gmail application does not use it) will be written in the Received header (there may be several such headers). Spam cutters look at these fields quite well and use the specified addresses for checks. Some mail.ru (not to mention self-made servers) are crazy enough to block emails based on only one IP from the header.

Answer 3

It shouldn't - the mail is delivered by the server, not the mobile application.
Although theoretically, it is possible to pull by the ears that some kind of anti-smm looks at the headers of the letter (the IP from which the message got to the mail server gets there), but this is unlikely.

Answer 4

It looks like you're sending emails via Gmail.
Go to the full version of Gmail, then to the "Sent Items" folder, then to any letter there, click on the three vertical dots in the upper right corner and select the "Show original" line there.
Make sure that the client's IP (either Spark or Canary) is NOT there!
Conclusion:
You are paranoid :) !