Your DNS Record is entered incorrectly :
this is how its showing :
dig -t txt thesecurityinstaller.co.uk
;; Warning: Message parser reports malformed message packet.
;; Truncated, retrying in TCP mode.
; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.68.rc1.el6_10.1 <<>> -t txt thesecurityinstaller.co.uk
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62769
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;thesecurityinstaller.co.uk. IN TXT
;; ANSWER SECTION:
thesecurityinstaller.co.uk. 3600 IN TXT "v=spf1 include:_spf.perfora.net include:_spf.kundenserver.de ip4:81.143.33.108 ~all"
thesecurityinstaller.co.uk. 3600 IN TXT "v=DMARC1\; p=none\; sp=none\; rua=mailto:james.wilson@thesecurityinstaller.co.uk\; ruf=mailto:james.wilson@thesecurityinstaller.co.uk\; rf=afrf\; pct=100\; ri=86400"
thesecurityinstaller.co.uk. 3600 IN TXT "default._domainkey IN TXT v=DKIM1\;p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAw9vP9oXU3IcKu8yOu0cXeCuFK+ZqM/L4EIa9+9yByi7R0ErB/uFLeclmHn0CPsV2REJk97jogL5P2sfT+I7WcRApGVD2Xv4v5krT5YrjKBMgO2u2bBF3yLTqs3e1pgOleI4BuemMaaz702ymmQgVCaIaP4ytoZylKY6ueDr5/XcWD7V" "btk0HO8iebJraimGF9PDs3Q/5izd+g2qxrpxyRatfBtgZL5mPnO7HzCIbmkTcSlAEUuY2HxSj/TTKpMA/LYZJlnaq9VzPuu5XLbPCRCKW43AJ9r3pEvZ6YfAuh2fuEmDpsZnqHX3BBIWMZloFB6hCI37M2X68rAeD3FeOCQIDAQAB\;t=y @ IN SPF v=spf1 mx a -all @ IN TXT v=spf1 mx a -all _dmarc IN TXT v=DMARC1\; p" "=none\; adkim=s\; aspf=r\; rua=mailto:dmarc-feedback@thesecurityinstaller.co.uk\; pct=100"
It should look like :
default_.domainkey.thesecurityinstaller.co.uk. 3600 IN TXT " v=DKIM1\;p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAw9vP9oXU3IcKu8yOu0cXeCuFK+ZqM/L4EIa9+9yByi7R0ErB/uFLeclmHn0CPsV2REJk97jogL5P2sfT+I7WcRApGVD2Xv4v5krT5YrjKBMgO2u2bBF3yLTqs3e1pgOleI4BuemMaaz702ymmQgVCaIaP4ytoZylKY6ueDr5/XcWD7V" "btk0HO8iebJraimGF9PDs3Q/5izd+g2qxrpxyRatfBtgZL5mPnO7HzCIbmkTcSlAEUuY2HxSj/TTKpMA/LYZJlnaq9VzPuu5XLbPCRCKW43AJ9r3pEvZ6YfAuh2fuEmDpsZnqHX3BBIWMZloFB6hCI37M2X68rAeD3FeOCQIDAQAB\;t=y"