first, please excuse my english.

I come here because I need help to resolve issues with DNS/MX records about my mail server.

I built my own mail server at home using debian 7, Iredmail server and afterlogic webmail.
Everything works good.

My mail server is SMTP capable, but I prefered to use my provider SMTP (provider is free SAS, a french provider that allow to use his SMTP service if the mail server is on one of his static IP)
So I have a static IP from free SAS, then I prefer to use the SMTP service from free SAS because I thing I have less risk of being seen as a spam.

I have my own domain pointing to my mail server.
This server is only doing mail server + webmail access, nothing much (apache, mysql, postfix ...).

Every port of my router are well forwarded.

My registrar is bookmyname.com.
It allows me to manage personnal DNS.

I am really newbie with DNS settings, but spent long time to try understansting what to do ...

Here it is what I set on my registrar interface:

    	www	 28800	 A	 mystaticIP
    	mydomain.com.	 3600	 TXT	 "v=spf1 ip4:mystaticIP -all"
    	@	 28800	 MX	 10 mydomain.com.
    	@	 28800	 A	 mystaticIP

So, It works but when I check my DNS with google apps tool box it results some errors I don't understand:

SPF MUST allow Google servers to send mail on behalf of domain.
No Google mail exchangers found. Relayhost configuration?
Info Help center article
ANY lookup SHOULD fit in one UDP response packet.

When I check with dnssniffer.com:

Multiple MX records WARNING. This domain has 1 MX record and is not using round robin , this can be a single point of failure.
I don't really understand what to do I would ask some specialists help please.

NB: I didn't know if it was safe to write my domain name and my IP so I replaced them, if it helps I could give the real domain and IP.

Thanks a lot for answer.